Cancer therapy using a combination of a hsp90 inhibitory compounds and a egfr inhibitor

ABSTRACT

A pharmaceutical combination comprising an EGFR inhibitor and an Hsp90 inhibitor according to the following formulae 
     
       
         
         
             
             
         
       
     
     a tautomer, or a pharmaceutically acceptable salt thereof, wherein the variables in the structural formulae are defined herein. Also provided are methods for treating a proliferative disorder in a subject in need thereof using pharmaceutical combinations disclosed herein.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/342,820, filed on Apr. 19, 2010, the entire disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Although tremendous advances have been made in elucidating the genomic abnormalities that cause malignant cancer cells, currently available chemotherapy remains unsatisfactory, and the prognosis for the majority of patients diagnosed with cancer remains dismal. Most chemotherapeutic agents act on a specific molecular target thought to be involved in the development of the malignant phenotype. However, a complex network of signaling pathways regulate cell proliferation and the majority of malignant cancers are facilitated by multiple genetic abnormalities in these pathways. Therefore, it is less likely that a therapeutic agent that acts on one molecular target will be fully effective in curing a patient who has cancer.

Heat shock proteins (HSPs) are a class of chaperone proteins that are up-regulated in response to elevated temperature and other environmental stresses, such as ultraviolet light, nutrient deprivation and oxygen deprivation. HSPs act as chaperones to other cellular proteins (called client proteins), facilitate their proper folding and repair and aid in the refolding of misfolded client proteins. There are several known families of HSPs, each having its own set of client proteins. The Hsp90 family is one of the most abundant HSP families accounting for about 1-2% of proteins in a cell that is not under stress and increasing to about 4-6% in a cell under stress. Inhibition of Hsp90 results in the degradation of its client proteins via the ubiquitin proteasome pathway. Unlike other chaperone proteins, the client proteins of Hsp90 are mostly protein kinases or transcription factors involved in signal transduction, and a number of its client proteins have been shown to be involved in the progression of cancer.

SUMMARY OF THE INVENTION

It is now found that certain triazolone Hsp90 inhibitors and EGFR inhibitor combinations are surprisingly effective at treating subjects with proliferative disorders without further increasing the side effect profile of the single agents. The particular combination therapies disclosed herein demonstrate surprising biological activity by demonstrating significant anticancer effects.

The present method utilizes Hsp90 inhibitors according to formulae (I) or (Ia) for the treatment of proliferative disorders, such as cancer, in combination with an EGFR inhibitor. The method includes the step of administering to a subject with cancer an Hsp90 inhibitor according to formulae (I) or (Ia) or a compound in Tables 1 or 2 and an EGFR inhibitor useful for the treatment of cancer. In one aspect, the administration of the Hsp90 inhibitor and the EGFR inhibitor are done concurrently. In another aspect, the administration of the Hsp90 inhibitor and the EGFR inhibitor are done sequentially. In another aspect, the administration of the Hsp90 inhibitor and the EGFR inhibitor are dosed independently. In any one of these embodiments, the EGFR inhibitor may be erlotinib, gefitinib or cetuximab. In any one of these embodiments, the Hsp90 inhibitor may be a compound represented by formulae (I) or (Ia), or a compound in Tables 1 or 2.

In another embodiment, a kit for administration of the combination therapy includes separate pharmaceutical compositions containing the Hsp90 inhibitor according to formulae (I) or (Ia) or a compound in Tables 1 or 2, and the EGFR inhibitor. In another embodiment, the kit includes one pharmaceutical composition containing both the Hsp90 inhibitor and the EGFR inhibitor. In any of these embodiments, each pharmaceutical composition may include one or more pharmaceutically acceptable carrier or diluent. In any one of these embodiments, the EGFR inhibitor may be erlotinib, gefitinib or cetuximab. In any one of these embodiments, the Hsp90 inhibitor may be a compound represented by formulae (I) or (Ia), or a compound in Tables 1 or 2.

In one embodiment, the method includes use of an Hsp90 inhibitor according to formulae (I) or (Ia) or a compound in Tables 1 or 2 for the manufacture of a medicament for treating cancer in combination with an EGFR inhibitor such as erlotinib, gefitinib or cetuximab.

In certain embodiments, the treatment utilizes an Hsp90 compound according to formulae (I) or (Ia) or a compound in Tables 1 or 2 with an EGFR inhibitor to help arrest, partially or fully, or reduce the development of multidrug resistant cancerous cells in a subject. In this embodiment, the combinations described herein may allow a reduced efficacious amount of the EGFR inhibitor given to a subject, because the Hsp90 inhibitor should inhibit the development of multidrug-resistant cancerous cells. In one embodiment, the EGFR inhibitor may be erlotinib, gefitinib or cetuximab. In another embodiment, the EGFR inhibitor is erlotinib.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of the embodiments, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.

FIG. 1 displays the results of a nude mouse xenograft study on the effect of Compound 26 on the in vivo growth rate of RERF-LC-AI^(IVP) human lung tumor cells. Tumor bearing animals (8 mice/group) were i.p. injected 5 times per week for a total of 15 doses (hatched bar) and the average tumor volumes for each group (error bars represent SEM) were determined every 3-4 days. Treatment with a dose of 200 mg/kg body weight of Compound 26 inhibited tumor growth, as did a dose of 75 mg/kg body weight of 17-AAG (both compounds were dosed at approximately their maximum tolerated doses in nude mice).

FIG. 2 demonstrates that treatment with Compound 26 does not cause overt toxicity in a nude mouse xenograft model using RERF-LC-AI^(IVP) human lung tumor cells (data derived from the same study presented in FIG. 5). Tumor bearing animals (8 mice/group) were i.p. injected 5 times per week for a total of 15 doses (hatched bar) and the cumulative average percent changes in body weights for each group relative to the start of dosing were determined every 2-3 days. Treatment with a dose of 200 mg/kg body weight of Compound 26 was not overtly toxic, as indicated by the minimal effects on the animal body weights in the test article-treated versus vehicle-treated groups.

FIG. 3 shows a SCID mouse xenograft study on the effects of the combination of Compound 1 plus erlotinib HCl on the in vivo growth rate of the human NSCLC cell line HCC827. Tumor-bearing animals (8 mice/group) were injected 1 time per week for a total of 3 doses (arrowheads) with vehicle alone, Compound 1 alone, erlotinib HCl alone or a combination of Compound 1 and erlotinib HCl dosed concurrently. Compound 1 was i.v. injected and erlotinib HCl was p.o. dosed. The average tumor volumes for each group (error bars represent SEM) were determined every 2-4 days. Single-agent treatments with either 50 mg/kg body weight of Compound 1, or 25 mg/kg body weight erlotinib HCl, moderately inhibited tumor growth. Concurrent treatment with a combination of 50 mg/kg body weight of Compound 1 plus 25 mg/kg body weight erlotinib HCl dramatically inhibited tumor growth and induced tumor regression. The efficacy observed for the combination treatment group was significantly greater than for either single agent alone (P<0.05; one-way ANOVA).

FIG. 4 shows the weight changes to the mice in the experiment detailed in FIG. 3.

FIG. 5 shows the PK profile of Compound 1 alone and in combination with erlotinib.

FIG. 6 shows the PK profile of erlotinib alone and in combination with Compound 1.

DETAILED DESCRIPTION OF THE INVENTION Definitions

Unless otherwise specified, the below terms used herein are defined as follows:

As used herein, the term “alkyl” means a saturated or unsaturated, straight chain or branched, non-cyclic hydrocarbon having from 1 to 10 carbon atoms. Representative straight chain alkyls include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl and n-decyl; while representative branched alkyls include isopropyl, sec-butyl, isobutyl, tert-butyl, isopentyl, 2-methylbutyl, 3-methylbutyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 2,3-dimethylbutyl, 2,3-dimethylpentyl, 2,4-dimethylpentyl, 2,3-dimethylhexyl, 2,4-dimethylhexyl, 2,5-dimethylhexyl, 2,2-dimethylpentyl, 2,2-dimethylhexyl, 3,3-dimtheylpentyl, 3,3-dimethylhexyl, 4,4-dimethylhexyl, 2-ethylpentyl, 3-ethylpentyl, 2-ethylhexyl, 3-ethylhexyl, 4-ethylhexyl, 2-methyl-2-ethylpentyl, 2-methyl-3-ethylpentyl, 2-methyl-4-ethylpentyl, 2-methyl-2-ethylhexyl, 2-methyl-3-ethylhexyl, 2-methyl-4-ethylhexyl, 2,2-diethylpentyl, 3,3-diethylhexyl, 2,2-diethylhexyl, 3,3-diethylhexyl, and the like. The term “(C₁-C₆)alkyl” means a saturated, straight chain or branched, non-cyclic hydrocarbon having from 1 to 6 carbon atoms. Alkyl groups included in compounds described herein may be optionally substituted with one or more substituents. Examples of unsaturated alkyls include vinyl, allyl, 1-butenyl, 2-butenyl, isobutylenyl, 1-pentenyl, 2-pentenyl, 3-methyl-1-butenyl, 2-methyl-2-butenyl, 2,3-dimethyl-2-butenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 1-heptenyl, 2-heptenyl, 3-heptenyl, 1-octenyl, 2-octenyl, 3-octenyl, 1-nonenyl, 2-nonenyl, 3-nonenyl, 1-decenyl, 2-decenyl, 3-decenyl, acetylenyl, propynyl, 1-butynyl, 2-butynyl, 1-pentynyl, 2-pentynyl, 3-methyl-1-butynyl, 4-pentynyl, 1-hexynyl, 2-hexynyl, 5-hexynyl, 1-heptynyl, 2-heptynyl, 6-heptynyl, 1-octynyl, 2-octynyl, 7-octynyl, 1-nonynyl, 2-nonynyl, 8-nonynyl, 1-decynyl, 2-decynyl, 9-decynyl, and the like. Alkyl groups included in compounds described herein may be optionally substituted with one or more substituents.

As used herein, the term “cycloalkyl” means a saturated or unsaturated, mono- or polycyclic, non-aromatic hydrocarbon having from 3 to 20 carbon atoms. Representative cycloalkyls include cyclopropyl, 1-methylcyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, octahydropentalenyl, cyclohexenyl, cyclooctenyl, cyclohexynyl, and the like. Cycloalkyl groups included in compounds described herein may be optionally substituted with one or more substituents.

As used herein, the term “alkylene” refers to an alkyl group that has two points of attachment. The term “(C₁-C₆)alkylene” refers to an alkylene group that has from one to six carbon atoms. Straight chain (C₁-C₆)alkylene groups are preferred. Non-limiting examples of alkylene groups include methylene (—CH₂—), ethylene (—CH₂CH₂—), n-propylene (—CH₂CH₂CH₂—), isopropylene (—CH₂CH(CH₃)—), and the like. Alkylene groups may be saturated or unsaturated, and may be optionally substituted with one or more substituents.

As used herein, the term “lower” refers to a group having up to four atoms. For example, a “lower alkyl” refers to an alkyl radical having from 1 to 4 carbon atoms, “lower alkoxy” refers to “—O—(C₁-C₄)alkyl.

As used herein, the term “haloalkyl” means an alkyl group, in which one or more, including all, the hydrogen radicals are replaced by a halo group(s), wherein each halo group is independently selected from —F, —Cl, —Br, and —I. For example, the term “halomethyl” means a methyl in which one to three hydrogen radical(s) have been replaced by a halo group. Representative haloalkyl groups include trifluoromethyl, bromomethyl, 1,2-dichloroethyl, 4-iodobutyl, 2-fluoropentyl, and the like.

As used herein, an “alkoxy” is an alkyl group which is attached to another moiety via an oxygen linker. Alkoxy groups included in compounds described herein may be optionally substituted with one or more substituents.

As used herein, a “haloalkoxy” is a haloalkyl group which is attached to another moiety via an oxygen linker.

As used herein, the term an “aromatic ring” or “aryl” means a mono- or polycyclic hydrocarbon, containing from 6 to 15 carbon atoms, in which at least one ring is aromatic. Examples of suitable aryl groups include phenyl, tolyl, anthracenyl, fluorenyl, indenyl, azulenyl, and naphthyl, as well as benzo-fused carbocyclic moieties such as 5,6,7,8-tetrahydronaphthyl. Aryl groups included in compounds described herein may be optionally substituted with one or more substituents. In one embodiment, the aryl group is a monocyclic ring, wherein the ring comprises 6 carbon atoms, referred to herein as “(C₆)aryl.”

As used herein, the term “aralkyl” means an aryl group that is attached to another group by a (C₁-C₆)alkylene group. Representative aralkyl groups include benzyl, 2-phenyl-ethyl, naphth-3-yl-methyl and the like. Aralkyl groups included in compounds described herein may be optionally substituted with one or more substituents.

As used herein, the term “heterocyclyl” means a monocyclic or a polycyclic, saturated or unsaturated, non-aromatic ring or ring system which typically contains 5- to 20-members and at least one heteroatom. A heterocyclic ring system can contain saturated ring(s) or unsaturated non-aromatic ring(s), or a mixture thereof. A 3- to 10-membered heterocycle can contain up to 5 heteroatoms, and a 7- to 20-membered heterocycle can contain up to 7 heteroatoms. Typically, a heterocycle has at least one carbon atom ring member. Each heteroatom is independently selected from nitrogen, which can be oxidized (e.g., N(O)) or quaternized, oxygen and sulfur, including sulfoxide and sulfone. The heterocycle may be attached via any heteroatom or carbon atom. Representative heterocycles include morpholinyl, thiomorpholinyl, pyrrolidinonyl, pyrrolidinyl, piperidinyl, piperazinyl, hydantoinyl, valerolactamyl, oxiranyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, tetrahydropyrindinyl, tetrahydropyrimidinyl, tetrahydrothiophenyl, tetrahydrothiopyranyl, and the like. A heteroatom may be substituted with a protecting group known to those of ordinary skill in the art, for example, a nitrogen atom may be substituted with a tert-butoxycarbonyl group. Furthermore, the heterocyclyl included in compounds described herein may be optionally substituted with one or more substituents. Only stable isomers of such substituted heterocyclic groups are contemplated in this definition.

As used herein, the term “heteroaryl”, or like terms, means a monocyclic or a polycyclic, unsaturated radical containing at least one heteroatom, in which at least one ring is aromatic. Polycyclic heteroaryl rings must contain at least one heteroatom, but not all rings of a polycyclic heteroaryl moiety must contain heteroatoms. Each heteroatom is independently selected from nitrogen, which can be oxidized (e.g., N(O)) or quaternized, oxygen and sulfur, including sulfoxide and sulfone. Representative heteroaryl groups include pyridyl, 1-oxo-pyridyl, furanyl, benzo[1,3]dioxolyl, benzo[1,4]dioxinyl, thienyl, pyrrolyl, oxazolyl, imidazolyl, thiazolyl, a isoxazolyl, quinolinyl, pyrazolyl, isothiazolyl, pyridazinyl, pyrimidinyl, pyrazinyl, a triazinyl, triazolyl, thiadiazolyl, isoquinolinyl, indazolyl, benzoxazolyl, benzofuryl, indolizinyl, imidazopyridyl, tetrazolyl, benzimidazolyl, benzothiazolyl, benzothiadiazolyl, benzoxadiazolyl, indolyl, tetrahydroindolyl, azaindolyl, imidazopyridyl, quinazolinyl, purinyl, pyrrolo[2,3]pyrimidinyl, pyrazolo[3,4]pyrimidinyl, imidazo[1,2-a]pyridyl, and benzothienyl. In one embodiment, the heteroaromatic ring is selected from 5-8 membered monocyclic heteroaryl rings. The point of attachment of a heteroaromatic or heteroaryl ring may be at either a carbon atom or a heteroatom. Heteroaryl groups included in compounds described herein may be optionally substituted with one or more substituents. As used herein, the term “(C₅)heteroaryl” means an heteroaromatic ring of 5 members, wherein at least one carbon atom of the ring is replaced with a heteroatom, such as, for example, oxygen, sulfur or nitrogen. Representative (C₅)heteroaryls include furanyl, thienyl, pyrrolyl, oxazolyl, imidazolyl, thiazolyl, isoxazolyl, pyrazolyl, isothiazolyl, pyrazinyl, triazolyl, thiadiazolyl, and the like. As used herein, the term “(C₆)heteroaryl” means an aromatic heterocyclic ring of 6 members, wherein at least one carbon atom of the ring is replaced with a heteroatom such as, for example, oxygen, nitrogen or sulfur.

Representative (C₆)heteroaryls include pyridyl, pyridazinyl, pyrazinyl, triazinyl, tetrazinyl, and the like.

As used herein, the term “heteroaralkyl” means a heteroaryl group that is attached to another group by a (C₁-C₆)alkylene. Representative heteroaralkyls include 2-(pyridin-4-yl)-propyl, 2-(thien-3-yl)-ethyl, imidazol-4-yl-methyl, and the like. Heteroaralkyl groups included in compounds described herein may be optionally substituted with one or more substituents.

As used herein, the term “halogen” or “halo” means —F, —Cl, —Br or —I.

Suitable substituents for an alkyl, alkylene, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl, aryl, aralkyl, heteroaryl, and heteroaralkyl groups include are those substituents which form a stable compound described herein without significantly adversely affecting the reactivity or biological activity of the compound described herein. Examples of substituents for an alkyl, alkylene, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl, aryl, aralkyl, heteroaryl, and heteroaralkyl include an alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl, aryl, heteroaryl, aralkyl, heteraralkyl, heteroalkyl, alkoxy, (each of which can be optionally and independently substituted), —C(O)NR²⁸R²⁹, —C(S)NR²⁸R²⁹, —C(NR³²)NR²⁸R²⁹, —NR³³C(O)R³¹, —NR³³C(S)R³¹, —NR³³C(NR³²)R³¹, halo, —OR³³, cyano, nitro, —C(O)R³³, —C(S)R³³, —C(NR³²)R³³, —NR²⁸R²⁹, —C(O)OR³³, —C(S)OR³³, —C(NR³²)OR³³, —OC(O)R³³, —OC(S)R³³, —OC(NR³²)R³³, —NR³⁰C(O)NR²⁸R²⁹, —NR³³C(S)NR²⁸R²⁹, —NR³³C(NR³²)NR²⁸R²⁹, —OC(O)NR²⁸R²⁹, —OC(S)NR²⁸R²⁹, —OC(NR³²)NR²⁸R²⁹, —NR³³C(O)OR³¹, —NR³³C(S)OR³¹, —NR³³C(NR³²)OR³¹, —S(O)_(k)R³³, —OS(O)_(k)R³³, —NR³³S(O)_(k)R³³, —S(O)_(k)NR²⁸R²⁹, —OS(O)_(k)NR²⁸R²⁹, —NR³³S(O)_(k)NR²⁸R²⁹, guanadino, —C(O)SR³¹, —C(S)SR³¹, —C(NR³²)SR³¹, —OC(O)OR³¹, —OC(S)OR³¹, —OC(NR³²)OR³¹, —SC(O)R³³, —SC(O)OR³¹, —SC(NR³²)OR³¹, —SC(S)R³³, —SC(S)OR³¹, —SC(O)NR²⁸R²⁹, —SC(NR³²)NR²⁸R²⁹, —SC(S)NR²⁸R²⁹, —SC(NR³²)R³³, —OS(O)_(k)OR³¹, —S(O)_(k)OR³¹, —NR³⁰S(O)_(k)OR³¹, —SS(O)_(k)R³³, —SS(O)_(k)OR³¹, —SS(O)_(k)NR²⁸R²⁹, —OP(O)(OR³¹)₂, or —SP(O)(OR³¹)₂. In addition, any saturated portion of an alkyl, cycloalkyl, alkylene, heterocyclyl, alkenyl, cycloalkenyl, alkynyl, aralkyl and heteroaralkyl groups, may also be substituted with ═O, ═S, or ═N—R³². Each R²⁸ and R²⁹ is independently H, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl, aryl, heteroaryl, aralkyl, or heteraralkyl, wherein each alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl, aryl, heteroaryl, aralkyl, or heteroalkyl represented by R²⁸ or R²⁹ is optionally and independently substituted. Each R³⁰, R³¹ and R³³ is independently H, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl, aryl, heteroaryl, aralkyl, or heteraralkyl, wherein each alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl, aryl, heteroaryl, aralkyl, and heteraralkyl represented by R³⁰ or R³¹ or R³³ is optionally and independently unsubstituted. Each R³² is independently H, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl, aryl, heteroaryl, aralkyl, heteraralkyl, —C(O)R³³, —C(O)NR²⁸R²⁹, —S(O)_(k)R³³, or —S(O)_(k)NR²⁸R²⁹, wherein each alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl, aryl, heteroaryl, aralkyl and heteraralkyl represented by R³² is optionally and independently substituted. The variable k is 0, 1 or 2. In some embodiments, suitable substituents include C1-C4 alkyl, C1-C4 haloalkyl, C1-C4 alkoxy, C1-C4 haloalkoxy, C1-C4 hydroxyalkyl, halo, or hydroxyl.

When a heterocyclyl, heteroaryl or heteroaralkyl group contains a nitrogen atom, it may be substituted or unsubstituted. When a nitrogen atom in the aromatic ring of a heteroaryl group has a substituent, the nitrogen may be oxidized or a quaternary nitrogen.

As used herein, the terms “subject”, “patient” and “mammal” are used interchangeably. The terms “subject” and “patient” refer to an animal (e.g., a bird such as a chicken, quail or turkey, or a mammal), preferably a mammal including a non-primate (e.g., a cow, pig, horse, sheep, rabbit, guinea pig, rat, cat, dog, and mouse) and a primate (e.g., a monkey, chimpanzee and a human), and more preferably a human. In one embodiment, the subject is a non-human animal such as a farm animal (e.g., a horse, cow, pig or sheep), or a pet (e.g., a dog, cat, guinea pig or rabbit). In another embodiment, the subject is a human.

Unless indicated otherwise, the compounds described herein containing reactive functional groups, such as, for example, carboxy, hydroxy, thiol and amino moieties, also include corresponding protected derivatives thereof. “Protected derivatives” are those compounds in which a reactive site or sites are blocked with one ore more protecting groups. Examples of suitable protecting groups for hydroxyl groups include benzyl, methoxymethyl, allyl, trimethylsilyl, tert-butyldimethylsilyl, acetate, and the like. Examples of suitable amine protecting groups include benzyloxycarbonyl, tert-butoxycarbonyl, tert-butyl, benzyl and fluorenylmethyloxy-carbonyl (Fmoc). Examples of suitable thiol protecting groups include benzyl, tert-butyl, acetyl, methoxymethyl and the like. Other suitable protecting groups are well known to those of ordinary skill in the art and include those found in T. W. GREENE, PROTECTING GROUPS IN ORGANIC SYNTHESIS, (John Wiley & Sons, Inc., 1981).

As used herein, the term “compound(s) described herein” or similar terms refers to a compound of formulae (I), or (Ia) or a compound in Tables 1 or 2 or a tautomer or pharmaceutically acceptable salt thereof. Also included in the scope of the embodiments are a solvate, clathrate, hydrate, polymorph, prodrug, or protected derivative of a compound of formulae (I), or (Ia), or a compound in Tables 1 or 2.

The compounds described herein may contain one or more chiral centers and/or double bonds and, therefore, exist as stereoisomers, such as double-bond isomers (i.e., geometric isomers), enantiomers or diastereomers. Each chemical structure shown herein, including the compounds described herein, encompass all of the corresponding compound' enantiomers, diastereomers and geometric isomers, that is, both the stereochemically pure form (e.g., geometrically pure, enantiomerically pure, or diastereomerically pure) and isomeric mixtures (e.g., enantiomeric, diastereomeric and geometric isomeric mixtures). In some cases, one enantiomer, diastereomer or geometric isomer will possess superior activity or an improved toxicity or kinetic profile compared to other isomers. In those cases, such enantiomers, diastereomers and geometric isomers of compounds described herein are preferred.

When a disclosed compound is named or depicted by structure, it is to be understood that solvates (e.g., hydrates) of the compound or a pharmaceutically acceptable salt thereof is also included. “Solvates” refer to crystalline forms wherein solvent molecules are incorporated into the crystal lattice during crystallization. Solvates may include water or nonaqueous solvents such as ethanol, isopropanol, DMSO, acetic acid, ethanolamine and ethyl acetate. When water is the solvent molecule incorporated into the crystal lattice of a solvate, it is typically referred to as a “hydrate”. Hydrates include stoichiometric hydrates as well as compositions containing variable amounts of water.

When a disclosed compound is named or depicted by structure, it is to be understood that the compound, including solvates thereof, may exist in crystalline forms, non-crystalline forms or a mixture thereof. The compounds or solvates may also exhibit polymorphism (i.e., the capacity to occur in different crystalline forms). These different crystalline forms are typically known as “polymorphs.” It is to be understood that when named or depicted by structure, the disclosed compounds and solvates (e.g., hydrates) also include all polymorphs thereof. Polymorphs have the same chemical composition but differ in packing, geometrical arrangement and other descriptive properties of the crystalline solid state. Polymorphs, therefore, may have different physical properties such as shape, density, hardness, deformability, stability and dissolution properties. Polymorphs typically exhibit different melting points, IR spectra and X-ray powder diffraction patterns, which may be used for identification. One of ordinary skill in the art will appreciate that different polymorphs may be produced, for example, by changing or adjusting the conditions used in crystallizing the compound. For example, changes in temperature, pressure or solvent may result in different polymorphs. In addition, one polymorph may spontaneously convert to another polymorph under certain conditions.

When a disclosed compound is named or depicted by structure, it is to be understood that clathrates (“inclusion compounds”) of the compound or its pharmaceutically acceptable salt, solvate or polymorph, are also included. “Clathrate” means a compound of the present invention, or a salt thereof, in the form of a crystal lattice that contains spaces (e.g., channels) that have a guest molecule trapped within (e.g., a solvent or water).

As used herein, and unless otherwise indicated, the term “prodrug” means a derivative of a compound that can hydrolyze, oxidize, or otherwise react under biological conditions (in vitro or in vivo) to provide a compound described herein. Prodrugs may become active upon such reaction under biological conditions, or they may have activity in their unreacted forms.

Examples of prodrugs contemplated herein include analogs or derivatives of compounds of formulae (I) or (Ia) or a compound in Tables 1 or 2 that comprise biohydrolyzable moieties such as biohydrolyzable amides, biohydrolyzable esters, biohydrolyzable carbamates, biohydrolyzable carbonates, biohydrolyzable ureides and phosphate analogues. Prodrugs can typically be prepared using well-known methods, such as those described by 1 BURGER'S MEDICINAL CHEMISTRY AND DRUG DISCOVERY, (Manfred E. Wolff Ed., 5^(th) ed. (1995)) 172-178, 949-982.

As used herein, “Hsp90” includes each member of the family of heat shock proteins having a mass of about 90-kiloDaltons. For example, in humans the highly conserved Hsp90 family includes the cytosolic Hsp90α and Hsp90β isoforms, as well as GRP94, which is found in the endoplasmic reticulum, and HSP75/TRAP1, which is found in the mitochondrial matrix.

“Epidermal growth factor receptor” or “EGFR”, as used herein, means any epidermal growth factor receptor (EGFR) protein, peptide, or polypeptide having EGFR or EGFR family activity (e.g., Her1, Her2, Her3 and/or Her4), such as encoded by EGFR Genbank Accession Nos. shown in Table I of U.S. patent application Ser. No. 10/923,354, filed on Aug. 20, 2004, or any other EGFR transcript derived from a EGFR gene and/or generated by EGFR translocation. The term “EGFR” is also meant to include other EGFR protein, peptide, or polypeptide derived from EGFR isoforms (e.g., Her1, Her2, Her3 and/or Her4), mutant EGFR genes, splice variants of EGFR genes, and EGFR gene polymorphisms. EGFR is a member of the type 1 subgroup of receptor tyrosine kinase family of growth factor receptors which play critical roles in cellular growth, differentiation and survival. Activation of these receptors typically occurs via specific ligand binding which results in hetero- or homodimerization between receptor family members, with subsequent autophosphorylation of the tyrosine kinase domain. Specific ligands which bind to EGFR include epidermal growth factor (EGF), transforming growth factor α (TGFα), amphiregulin and some viral growth factors. Activation of EGFR triggers a cascade of intracellular signaling pathways involved in both cellular proliferation (the ras/raf/MAP kinase pathway) and survival (the PI3 kinase/Akt pathway). Members of this family, including EGFR and HER2, have been directly implicated in cellular transformation.

A number of human malignancies are associated with aberrant or overexpression of EGFR and/or overexpression of its specific ligands. Gullick, Br. Med. Bull. (1991), 47:87-98; Modijtahedi & Dean, Int. J. Oncol. (1994), 4:277-96; Salomon, et al., Crit. Rev. Oncol. Hematol. (1995), 19:183-232. Aberrant or overexpression of EGFR has been associated with an adverse prognosis in a number of human cancers, including head and neck, breast, colon, prostate, lung (e.g., NSCLC, adenocarcinoma and squamous lung cancer), ovarian, gastrointestinal cancers (gastric, colon, pancreatic), renal cell cancer, bladder cancer, glioma, gynecological carcinomas and prostate cancer. In some instances, overexpression of tumor EGFR has been correlated with both chemoresistance and a poor prognosis. Lei, et al., Anti-cancer Res. (1999), 19:221-28; Veale, et al., Br. J. Cancer (1993); 68:162-65.

Gliomas are another type of cancer that is characterized by the amplification and/or mutation of the EGFR gene. One of the most common mutations in the EGFR gene is a deletion of exons 2-7 which results in a truncated form of EGFR in which amino acids 6-273 of the extracellular domain are replaced with a single glycine residue. This mutation is called EGFRvIII and is expressed in about half of all glioblastomas. EGFRvIII is unable to bind EGF and TGFα and has constitutive, ligand-independent tyrosine kinase activity. Hsp90 co-purifies with EGFRvIII, indicating that Hsp90 complexes with EGFRvIII. Moreover, the Hsp90 inhibitor geldanamycin, a benzoquinone ansamycin antibiotic, is able to decrease the expression of EGFRvIII, indicating that interaction with Hsp90 is essential to maintain high expression levels of EGFRvIII. Lavictoire, et al., J. Biological Chem. (2003), 278(7):5292-5299. These results demonstrate that inhibiting the activity of Hsp90 is an effective strategy for treating cancers that are associated with inappropriate EGFR activity.

An “EGFR inhibitor”, as used herein, includes any compound that disrupts EGFR production within a cell. Activation of EGFR leads to the Ras signaling cascade that results in uncontrolled cell proliferation. EGFR inhibitors include monoclonal antibodies that bind EGFR to inactivate it, and compounds that bind to the tyrosine kinase domain of EGFR to inhibit it. EGFR inhibitors include drugs such as erlotinib, gefitinib, and cetuximab. Particularly, erlotinib is described in U.S. Pat. Nos. 5,747,498, 6,900,221, 7,087,613, and RE41065. In addition, the EGFR inhibitors employed herein may also be called other names such as Tarceva®, Iressa®, and Erbitux®, which are all well-known anti-cancer drugs. A more detailed description of some of these drugs is presented below.

Gefitinib, a chemotherapeutic agent that inhibits the activity of EGFR, has been found to be highly efficacious in a subset of lung cancer patients that have mutations in the tyrosine kinase domain of EGFR. In the presence of EGF, these mutants displayed two to three times higher activity than wild type EGFR. In addition, wild type EGFR was internalized by the cells and down-regulated after 15 minutes, whereas mutant EGFR was internalized more slowly and continued to be activated for up to three hours. Lynch, et al., New Eng. J. Med. (2006), 350:2129-2139.

Another chemotherapeutic agent that inhibits EGFR is erlotinib (Tarceva®). Erlotinib is approved for advanced unresectable or metastatic pancreatic cancer and metastatic non-small cell lung cancer. In addition to being a potent EGFR inhibitor, erlotinib also potently inhibits the JAK2 mutant JAK2V617F, which is found in many myeloproliferative disorders, such as polycythemia vera.

As used herein, a “proliferative disorder” or a “hyperproliferative disorder,” and other equivalent terms, means a disease or medical condition involving pathological growth of cells. Proliferative disorders include cancer, smooth muscle cell proliferation, systemic sclerosis, cirrhosis of the liver, adult respiratory distress syndrome, idiopathic cardiomyopathy, lupus erythematosus, retinopathy, (e.g., diabetic retinopathy or other retinopathies), cardiac hyperplasia, reproductive system associated disorders such as benign prostatic hyperplasia and ovarian cysts, pulmonary fibrosis, endometriosis, fibromatosis, harmatomas, lymphangiomatosis, sarcoidosis and desmoid tumors. Non-cancerous proliferative disorders also include hyperproliferation of cells in the skin such as psoriasis and its varied clinical forms, Reiter's syndrome, pityriasis rubra pilaris, hyperproliferative variants of disorders of keratinization (e.g., actinic keratosis, senile keratosis), scleroderma, and the like. In one embodiment, the proliferative disorder is a myeloproliferative disorder. In one aspect, the myeloproliferative disorder is polycythemia vera, idiopathic myelofirbrosis, myelodysplastic syndrome, psoriasis or essential thrombocythemia. In one embodiment, the proliferative disorder expresses JAK2V617F mutation of JAK2. In an aspect of this embodiment, the proliferative disorder is polycythemia vera, idiopathic myelofirbrosis, or essential thrombocythemia. In one aspect, the proliferative disorder is polycythemia vera.

As used herein, the term “pharmaceutically acceptable salt” refers to a salt prepared from a compound of formulae (I) or (Ia) or a compound in Tables 1 or 2 having an acidic functional group, such as a carboxylic acid functional group, and a pharmaceutically acceptable inorganic or organic base. Suitable bases include hydroxides of alkali metals such as sodium, potassium, and lithium; hydroxides of alkaline earth metal such as calcium and magnesium; hydroxides of other metals, such as aluminum and zinc; ammonia, and organic amines, such as unsubstituted or hydroxy-substituted mono-, di-, or trialkylamines; dicyclohexylamine; tributyl amine; pyridine; N-methyl,N-ethylamine; diethylamine; triethylamine; mono-, bis-, or tris-(2-hydroxy-lower alkyl amines), such as mono-, bis-, or tris-(2-hydroxyethyl)amine, 2-hydroxy-tert-butylamine, or tris-(hydroxymethyl)methylamine, N,N,-di-lower alkyl-N-(hydroxy lower alkyl)-amines, such as N,N-dimethyl-N-(2-hydroxyethyl)amine, or tri-(2-hydroxyethyl)amine; N-methyl-D-glucamine; and amino acids such as arginine, lysine, and the like. The term “pharmaceutically acceptable salt” also refers to a salt prepared from a compound of formulae (I) or (Ia) or a compound in Tables 1 or 2 having a basic functional group, such as an amine functional group, and a pharmaceutically acceptable inorganic or organic acid. Suitable acids include hydrogen sulfate, citric acid, acetic acid, oxalic acid, hydrochloric acid (HCl), hydrogen bromide (HBr), hydrogen iodide (HI), nitric acid, hydrogen bisulfide, phosphoric acid, isonicotinic acid, oleic acid, tannic acid, pantothenic acid, saccharic acid, lactic acid, salicylic acid, tartaric acid, bitartratic acid, ascorbic acid, succinic acid, maleic acid, besylic acid, fumaric acid, gluconic acid, glucaronic acid, formic acid, benzoic acid, glutamic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, pamoic acid and p-toluenesulfonic acid.

As used herein, the term “pharmaceutically acceptable solvate,” is a solvate formed from the association of one or more pharmaceutically acceptable solvent molecules to one of the compounds of formulae (I) or (Ia) or a compound in Tables 1 or 2. The term “solvate” includes hydrates, e.g., hemihydrate, monohydrate, dihydrate, trihydrate, tetrahydrate, and the like.

A pharmaceutically acceptable carrier may contain inert ingredients which do not unduly inhibit the biological activity of the compound(s). The pharmaceutically acceptable carriers should be biocompatible, i.e., non-toxic, non-inflammatory, non-immunogenic and devoid of other undesired reactions upon the administration to a subject. Standard pharmaceutical formulation techniques can be employed, such as those described in REMINGTON, J. P., REMINGTON'S PHARMACEUTICAL SCIENCES (Mack Pub. Co., 17^(th) ed., 1985). Suitable pharmaceutical carriers for parenteral administration include, for example, sterile water, physiological saline, bacteriostatic saline (saline containing about 0.9% mg/ml benzyl alcohol), phosphate-buffered saline, Hank's solution, Ringer's-lactate, and the like. Methods for encapsulating compositions, such as in a coating of hard gelatin or cyclodextran, are known in the art. See BAKER, ET AL., CONTROLLED RELEASE OF BIOLOGICAL ACTIVE AGENTS, (John Wiley and Sons, 1986).

As used herein, the term “effective amount” refers to an amount of a compound described herein which is sufficient to reduce or ameliorate the severity, duration, progression, or onset of a disease or disorder, delay onset of a disease or disorder, retard or halt the advancement of a disease or disorder, cause the regression of a disease or disorder, prevent or delay the recurrence, development, onset or progression of a symptom associated with a disease or disorder, or enhance or improve the therapeutic effect(s) of another therapy. In one embodiment, the disease or disorder is a proliferative disorder. The precise amount of compound administered to a subject will depend on the mode of administration, the type and severity of the disease or condition and on the characteristics of the subject, such as general health, age, sex, body weight and tolerance to drugs. For example, for a proliferative disease or disorder, determination of an effective amount will also depend on the degree, severity and type of cell proliferation. The skilled artisan will be able to determine appropriate dosages depending on these and other factors. When co-administered with other therapeutic agents, e.g., when co-administered with an anti-cancer agent, an “effective amount” of any additional therapeutic agent(s) will depend on the type of drug used. Suitable dosages are known for approved therapeutic agents and can be adjusted by the skilled artisan according to the condition of the subject, the type of condition(s) being treated and the amount of a compound of the invention being used. In cases where no amount is expressly noted, an effective amount should be assumed. Non-limiting examples of an effective amount of a compound described herein are provided herein below. In a specific embodiment, the invention provides a method of treating, managing, or ameliorating a disease or disorder, e.g. a proliferative disorder, or one or more symptoms thereof, said method comprising administering to a subject in need thereof a dose of the Hsp90 inhibitor at least 150 μg/kg, at least 250 μg/kg, at least 500 μg/kg, at least 1 mg/kg, at least 5 mg/kg, at least 10 mg/kg, at least 25 mg/kg, at least 50 mg/kg, at least 75 mg/kg, at least 100 mg/kg, at least 125 mg/kg, at least 150 mg/kg, or at least 200 mg/kg or more of one or more compounds described herein once every day, once every 2 days, once every 3 days, once every 4 days, once every 5 days, once every 6 days, once every 7 days, once every 8 days, once every 10 days, once every two weeks, once every three weeks, or once a month.

The dosage of an individual EGFR inhibitor used in combination therapy may be equal to or lower than the dose of an individual therapeutic agent when given independently to treat, manage, or ameliorate a disease or disorder, or one or more symptoms thereof. In one embodiment, the disease or disorder being treated with a combination therapy is a proliferative disorder. In another embodiment, the proliferative disorder is cancer. The recommended dosages of therapeutic agents currently used for the treatment, management, or amelioration of a disease or disorder, or one or more symptoms thereof, can obtained from any reference in the art. See, e.g., GOODMAN & GILMAN'S THE PHARMACOLOGICAL BASIS OF BASIS OF THERAPEUTICS 9^(TH) ED, (Hardman, et al., Eds., NY:Mc-Graw-Hill (1996)); PHYSICIAN'S DESK REFERENCE 57^(TH) ED. (Medical Economics Co., Inc., Montvale, N.J. (2003)).

As used herein, the terms “treat”, “treatment” and “treating” refer to the reduction or amelioration of the progression, severity and/or duration of a disease or disorder, delay of the onset of a disease or disorder, or the amelioration of one or more symptoms (preferably, one or more discernible symptoms) of a disease or disorder, resulting from the administration of one or more therapies (e.g., one or more therapeutic agents such as a compound of the invention). The terms “treat”, “treatment” and “treating” also encompass the reduction of the risk of developing a disease or disorder, and the delay or inhibition of the recurrence of a disease or disorder. In one embodiment, the disease or disorder being treated is a proliferative disorder such as cancer. In specific embodiments, the terms “treat”, “treatment” and “treating” refer to the amelioration of at least one measurable physical parameter of a disease or disorder, such as growth of a tumor, not necessarily discernible by the patient. In other embodiments the terms “treat”, “treatment” and “treating” refer to the inhibition of the progression of a disease or disorder, e.g., a proliferative disorder, either physically by the stabilization of a discernible symptom, physiologically by the stabilization of a physical parameter, or both. In another embodiment, the terms “treat”, “treatment” and “treating” of a proliferative disease or disorder refers to the reduction or stabilization of tumor size or cancerous cell count, and/or delay of tumor formation. In another embodiment, the terms “treat”, “treating” and “treatment” also encompass the administration of a compound described herein as a prophylactic measure to patients with a predisposition (genetic or environmental) to any disease or disorder described herein.

As used herein, the terms “therapeutic agent” and “therapeutic agents” refer to any agent(s) that can be used in the treatment of a disease or disorder, e.g. a proliferative disorder, or one or more symptoms thereof. In certain embodiments, the term “therapeutic agent” refers to a compound described herein. In certain other embodiments, the term “therapeutic agent” does not refer to a compound described herein. Preferably, a therapeutic agent is an agent that is known to be useful for, or has been or is currently being used for the treatment of a disease or disorder, e.g., a proliferative disorder, or one or more symptoms thereof.

As used herein, the term “synergistic” refers to a combination of a compound described herein and another therapeutic agent, which, when taken together, is more effective than the additive effects of the individual therapies. A synergistic effect of a combination of therapies (e.g., a combination of therapeutic agents) permits the use of lower dosages of one or more of the therapeutic agent(s) and/or less frequent administration of said agent(s) to a subject with a disease or disorder, e.g., a proliferative disorder. The ability to utilize lower the dosage of one or more therapeutic agent and/or to administer said therapeutic agent less frequently reduces the toxicity associated with the administration of said agent to a subject without reducing the efficacy of said therapy in the treatment of a disease or disorder. In addition, a synergistic effect can result in improved efficacy of agents in the prevention, management or treatment of a disease or disorder, e.g. a proliferative disorder. Finally, a synergistic effect of a combination of therapies may avoid or reduce adverse or unwanted side effects associated with the use of either therapeutic agent alone.

As used herein, the phrase “side effects” encompasses unwanted and adverse effects of a therapeutic agent. Side effects are always unwanted, but unwanted effects are not necessarily adverse. An adverse effect from a therapeutic agent might be harmful or uncomfortable or risky to a subject. Side effects include fever, chills, lethargy, gastrointestinal toxicities (including gastric and intestinal ulcerations and erosions), nausea, vomiting, neurotoxicities, nephrotoxicities, renal toxicities (including such conditions as papillary necrosis and chronic interstitial nephritis), hepatic toxicities (including elevated serum liver enzyme levels), myelotoxicities (including leukopenia, myelosuppression, thrombocytopenia and anemia), dry mouth, metallic taste, prolongation of gestation, weakness, somnolence, pain (including muscle pain, bone pain and headache), hair loss, asthenia, dizziness, extra-pyramidal symptoms, akathisia, cardiovascular disturbances and sexual dysfunction.

As used herein, the term “in combination” refers to the use of more than one therapeutic agent. The use of the term “in combination” does not restrict the order in which said therapeutic agents are administered to a subject with a disease or disorder, e.g., a proliferative disorder. A first therapeutic agent, such as a compound described herein, can be administered prior to (e.g., 5 minutes, 15 minutes, 30 minutes, 45 minutes, 1 hour, 2 hours, 4 hours, 6 hours, 12 hours, 24 hours, 48 hours, 72 hours, 96 hours, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 8 weeks, or 12 weeks before), concomitantly with, or subsequent to (e.g., 5 minutes, 15 minutes, 30 minutes, 45 minutes, 1 hour, 2 hours, 4 hours, 6 hours, 12 hours, 24 hours, 48 hours, 72 hours, 96 hours, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 8 weeks, or 12 weeks after) the administration of a second therapeutic agent, such as an anti-cancer agent, to a subject with a disease or disorder, e.g. a proliferative disorder, such as cancer. In one embodiment, the Hsp90 inhibitor and the EGFR inhibitor are dosed on independent schedules. In another embodiment, the Hsp90 inhibitor and the EGFR inhibitor are dosed on approximately the same schedule. In another embodiment, the Hsp90 inhibitor and the EGFR inhibitor are dosed concurrently or sequentially on the same day.

As used herein, the terms “therapies” and “therapy” can refer to any protocol(s), method(s), and/or agent(s) that can be used in the prevention, treatment, management, or amelioration of a disease or disorder, e.g., a proliferative disorder, or one or more symptoms thereof.

A used herein, a “protocol” includes dosing schedules and dosing regimens. The protocols herein are methods of use and include therapeutic protocols.

As used herein, a composition that “substantially” comprises a compound means that the composition contains more than about 80% by weight, more preferably more than about 90% by weight, even more preferably more than about 95% by weight, and most preferably more than about 97% by weight of the compound.

As used herein, a racemic mixture means about 50% of one enantiomer and about 50% of is corresponding enantiomer of the molecule. The combination encompasses all enantiomerically-pure, enantiomerically-enriched, diastereomerically pure, diastereomerically enriched, and racemic mixtures of the compounds described herein. Enantiomeric and diastereomeric mixtures can be resolved into their component enantiomers or diastereomers by well known methods, such as chiral-phase gas chromatography, chiral-phase high performance liquid chromatography, crystallizing the compound as a chiral salt complex, or crystallizing the compound in a chiral solvent. Enantiomers and diastereomers can also be obtained from diastereomerically- or enantiomerically-pure intermediates, reagents, and catalysts by well known asymmetric synthetic methods.

The compounds described herein are defined by their chemical structures and/or chemical names. Where a compound is referred to by both a chemical structure and a chemical name, and the chemical structure and the chemical name conflict, the chemical structure is determinative of the compound's identity.

When administered to a subject (e.g., a non-human animal for veterinary use or for improvement of livestock or to a human for clinical use), the compounds described herein are administered in an isolated form, or as the isolated form in a pharmaceutical composition. As used herein, “isolated” means that the compounds described herein are separated from other components of either: (a) a natural source, such as a plant or cell, preferably bacterial culture, or (b) a synthetic organic chemical reaction mixture. Preferably, the compounds of the invention are purified via conventional techniques. As used herein, “purified” means that when isolated, the isolate contains at least 95%, preferably at least 98%, of a compound described herein by weight of the isolate either as a mixture of stereoisomers, or as a diastereomeric or enantiomeric pure isolate.

Only those choices and combinations of substituents that result in a stable structure are contemplated. Such choices and combinations will be apparent to those of ordinary skill in the art and may be determined without undue experimentation.

The invention can be understood more fully by reference to the following detailed description and illustrative examples, which are intended to exemplify non-limiting embodiments of the invention.

The methods described herein utilize triazolone Hsp90 inhibitory compounds listed in Tables 1 or 2, or a compound represented by Formulae (I) or (Ia):

-   -   or a tautomer, or a pharmaceutically acceptable salt thereof,         wherein:     -   Z is OH, SH, or NH₂;     -   X is CR₄ or N;     -   R₁ is —H, —OH, —SH, an optionally substituted alkyl, an         optionally substituted alkenyl, an optionally substituted         alkynyl, an optionally substituted cycloalkyl, an optionally         substituted cycloalkenyl, an optionally substituted         heterocyclyl, an optionally substituted aryl, an optionally         substituted heteroaryl, an optionally substituted aralkyl, an         optionally substituted heteraralkyl, halo, cyano, nitro,         guanadino, a haloalkyl, a heteroalkyl, an alkoxy or cycloalkoxy,         a haloalkoxy, —NR₁₀R₁₁, —OR₇, —C(O)R₇, —C(O)OR₇, —C(S)R₇,         —C(O)SR₇, —C(S)SR₇, —C(S)OR₇, —C(S)NR₁₀R₁₁, —C(NR₈)OR₇,         —C(NR₈)R₇, —C(NR₈)NR₁₀R₁₁, —C(NR₈)SR₇, —OC(O)R₇, —OC(O)OR₇,         —OC(S)OR₇, —OC(NR₈)OR₇, —SC(O)R₇, —SC(O)OR₇, —SC(NR₈)OR₇,         —OC(S)R₇, —SC(S)R₇, —SC(S)OR₇, —OC(O)NR₁₀R₁₁, —OC(S)NR₁₀R₁₁,         —OC(NR₈)NR₁₀R₁₁, —SC(O)NR₁₀R₁₁, —SC(NR₈)NR₁₀R₁₁, —SC(S)NR₁₀R₁₁,         —OC(NR₈)R₇, —SC(NR₈)R₇, —C(O)NR₁₀R₁₁, —NR₈C(O)R₇, —NR₇C(S)R₇,         —NR₇C(S)OR₇, —NR₇C(NR₈)R₇, —NR₇C(O)OR₇, —NR₇C(NR₈)OR₇,         —NR₇C(O)NR₁₀R₁₁, —NR₇C(S)NR₁₀R₁₁, —NR₇C(NR₈)NR₁₀R₁₁, —SR₇,         —S(O)_(p)R₇, —OS(O)_(p)R₇, —OS(O)_(p)OR₇, —OS(O)_(p)NR₁₀R₁₁,         —S(O)_(p)OR₇, —NR₈S(O)_(p)R₇, —NR₇S(O)_(p)NR₁₀R¹¹,         —NR₇S(O)_(p)OR₇, —S(O)_(p)NR₁₀R₁₁, —SS(O)_(p)R₇, —SS(O)_(p)OR₇,         —SS(O)_(p)NR₁₀R₁₁, —OP(O)(OR₇)₂, or —SP(O)(OR₇)₂;     -   R₂ is —H, —OH, —SH, —NR₇H, —OR₁₅, —SR₁₅, —NHR₁₅, —O(CH₂)_(m)OH,         —O(CH₂)_(m)SH, —O(CH₂)_(m)NR₇H, —S(CH₂)_(m)OH, —S(CH₂)_(m)SH,         —S(CH₂)_(m)NR₇H, —OC(O)NR₁₀R₁₁, —SC(O)NR₁₀R₁₁, —NR₇C(O)NR₁₀R₁₁,         —OC(O)R₇, —SC(O)R₇, —NR₇C(O)R₇, —OC(O)OR₇, —SC(O)OR₇,         —NR₇C(O)OR₇, —OCH₂C(O)R₇, —SCH₂C(O)R₇, —NR₇CH₂C(O)R₇,         —OCH₂C(O)OR₇, —SCH₂C(O)OR₇, —NR₇CH₂C(O)OR₇, —OCH₂C(O)NR₁₀R₁₁,         —SCH₂C(O)NR₁₀R₁₁, —NR₇CH₂C(O)NR₁₁R₁₁, —OS(O)_(p)R₇,         —SS(O)_(p)R₇, —NR₇S(O)_(p)R₇, —OS(O)_(p)NR₁₀R₁₁,         —SS(O)_(p)NR₁₀R₁₁, —NR₇S(O)_(p)NR₁₀R₁₁, —OS(O)_(p)OR₇,         —SS(O)_(p)OR₇, —NR₇S(O)_(p)OR₇, —OC(S)R₇, —SC(S)R₇, —NR₇C(S)R₇,         —OC(S)OR₇, —SC(S)OR₇, —NR₇C(S)OR₇, —OC(S)NR₁₀R₁₁, —SC(S)NR₁₀R₁₁,         —NR₇C(S)NR₁₀R₁₁, —OC(NR₈)R₇, —SC(NR₈)R₇, —NR₇C(NR₈)R₇,         —OC(NR₈)OR₇, —SC(NR₈)OR₇, —NR₇C(NR₈)OR₇, —OC(NR₈)NR₁₀R₁₁,         —SC(NR₈)NR₁₀R₁₁, or —NR₇C(NR₈)NR₁₀R₁₁;     -   R₃ is —H, an optionally substituted alkyl, an optionally         substituted alkenyl, an optionally substituted alkynyl, an         optionally substituted cycloalkyl, an optionally substituted         cycloalkenyl, an optionally substituted heterocyclyl, an         optionally substituted aryl, an optionally substituted         heteroaryl, an optionally substituted aralkyl, an optionally         substituted heteraralkyl, hydroxyalkyl, alkoxyalkyl, a         haloalkyl, a heteroalkyl, —C(O)R₇, —(CH₂)_(m)C(O)OR₇, —C(O)OR₇,         —OC(O)R₇, —C(O)NR₁₀R₁₁, —S(O)_(p)R₇, —S(O)_(p)OR₇, or         —S(O)_(p)NR₁₀R₁₁;     -   R₄ is —H, —OH, an optionally substituted alkyl, an optionally         substituted alkenyl, an optionally substituted alkynyl, an         optionally substituted cycloalkyl, an optionally substituted         cycloalkenyl, an optionally substituted heterocyclyl, an         optionally substituted aryl, an optionally substituted         heteroaryl, an optionally substituted aralkyl, an optionally         substituted heteraralkyl, hydroxyalkyl, alkoxyalkyl, halo,         cyano, nitro, guanadino, a haloalkyl, a heteroalkyl, —C(O)R₇,         —C(O)OR₇, —OC(O)R₇, —C(O)NR₁₀R₁₁, —NR₈C(O)R₇, —SR₇, —S(O)_(p)R₇,         —OS(O)_(p)R₇, —S(O)_(p)OR₇, —NR₈S(O)_(p)R₇, —S(O)_(p)NR₁₀R₁₁, or         R₄₃ and R₄₄ taken together with the carbon atoms to which they         are attached form an optionally substituted cycloalkenyl, an         optionally substituted aryl, an optionally substituted         heterocyclyl, or an optionally substituted heteroaryl;     -   R₇ and R₈, for each occurrence, are, independently, —H, an         optionally substituted alkyl, an optionally substituted alkenyl,         an optionally substituted alkynyl, an optionally substituted         cycloalkyl, an optionally substituted cycloalkenyl, an         optionally substituted heterocyclyl, an optionally substituted         aryl, an optionally substituted heteroaryl, an optionally         substituted aralkyl, or an optionally substituted heteraralkyl;     -   R₁₀ and R₁₁, for each occurrence, are independently —H, an         optionally substituted alkyl, an optionally substituted alkenyl,         an optionally substituted alkynyl, an optionally substituted         cycloalkyl, an optionally substituted cycloalkenyl, an         optionally substituted heterocyclyl, an optionally substituted         aryl, an optionally substituted heteroaryl, an optionally         substituted aralkyl, or an optionally substituted heteraralkyl;         or R₁₀ and R₁₁, taken together with the nitrogen to which they         are attached, form an optionally substituted heterocyclyl or an         optionally substituted heteroaryl;     -   R₁₅, for each occurrence, is independently, a lower alkyl;     -   p, for each occurrence, is, independently, 1 or 2; and     -   m, for each occurrence, is independently, 1, 2, 3, or 4.

In one embodiment, in formula (I) or (Ia), X is CR₄.

In another embodiment, in formula (I) or (Ia), X is N.

In another embodiment, in formula (I) or (Ia), R₁ is selected from the group consisting of —H, lower alkyl, lower alkoxy, lower cycloalkyl, and lower cycloalkoxy.

In another embodiment, in formula (I) or (Ia), R₁ is selected from the group consisting of —H, methyl, ethyl, propyl, isopropyl, cyclopropyl, methoxy, ethoxy, propoxy, and cyclopropoxy.

In another embodiment, in formula (I) or (Ia), R₃ is selected from the group consisting of —H, a lower alkyl, a lower cycloalkyl, —C(O)N(R₂₇)₂, and —C(O)OH, wherein R₂₇ is —H or a lower alkyl.

In another embodiment, in formula (I) or (Ia), R₃ is selected from the group consisting of —H, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, —C(O)OH, —(CH₂)_(m)C(O)OH, —CH₂OCH₃, —CH₂CH₂OCH₃, and —C(O)N(CH₃)₂.

In one embodiment, R₄ is H or a lower alkyl.

In another embodiment, in formula (I) or (Ia), R₄ is selected from the group consisting of —H, methyl, ethyl, propyl, isopropyl or cyclopropyl.

In another embodiment, in formula (I) or (Ia), R₁ is selected from the group consisting of —H, —OH, —SH, —NH₂, a lower alkoxy and a lower alkyl amino.

In another embodiment, in formula (I) or (Ia), R₁ is selected from the group consisting of —H, —OH, methoxy and ethoxy.

In another embodiment, in formula (I) or (Ia), Z is —OH.

In another embodiment, in formula (I) or (Ia), Z is —SH.

In another embodiment, in formula (I) or (Ia), R₂ is selected from the group consisting of —H, —OH, —SH, —NH₂, a lower alkoxy and a lower alkyl amino.

In another embodiment, in formula (I) or (Ia), R₂ is selected from the group consisting of —H, —OH, methoxy, and ethoxy.

In another embodiment, in formula (I) or (Ia), R₁ is selected from the group consisting of —H, methyl, ethyl, propyl, isopropyl, cyclopropyl, methoxy, ethoxy, propoxy, and cyclopropoxy;

R₃ is selected from the group consisting of —H, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, —C(O)OH, —(CH₂)_(m)C(O)OH, —CH₂OCH₃, —CH₂CH₂OCH₃, and —C(O)N(CH₃)₂; R₄ is selected from the group consisting of —H, methyl, ethyl, propyl, isopropyl or cyclopropyl; R₂ is selected from the group consisting of —H, —OH, —SH, —NH₂, a lower alkoxy and a lower alkyl amino; and Z is OH.

In another embodiment, in formula (I) or (Ia), R₁ is selected from the group consisting of —H, methyl, ethyl, propyl, isopropyl, cyclopropyl, methoxy, ethoxy, propoxy, and cyclopropoxy;

R₃ is selected from the group consisting of —H, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, —C(O)OH, —(CH₂)_(m)C(O)OH, —CH₂OCH₃, —CH₂CH₂OCH₃, and —C(O)N(CH₃)₂; R₄ is selected from the group consisting of —H, methyl, ethyl, propyl, isopropyl or cyclopropyl; R₂ is selected from the group consisting of —H, —OH, —SH, —NH₂, a lower alkoxy and a lower alkyl amino; and Z is SH.

In another embodiment, the compound is selected from the group consisting of:

-   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(1,3-dimethyl-indol-5-yl)-5-hydroxy-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1,3-dimethyl-indol-5-yl)-5-hydroxy-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-methyl-indol-5-yl)-5-hydroxy-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-isopropyl-indol-4-yl)-5-hydroxy-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-methyl-indazol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-methyl-indazol-6-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxyphenyl)-4-(1-ethyl-indol-4-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxyphenyl)-4-(1-isopropyl-indol-4-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxyphenyl)-4-(indol-4-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxyphenyl)-4-(1-methoxyethyl-indol-4-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(1-isopropyl-indol-4-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxyphenyl)-4-(1-dimethylcarbamoyl-indol-4-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(1-propyl-indol-4-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(1,2,3-trimethyl-indol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(2,3-dimethyl-indol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(1-acetyl-2,3-dimethyl-indol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(1-propyl-2,3-dimethyl-indol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(1-n-butyl-indol-4-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(1-n-pentyl-indol-4-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(1-n-hexyl-indol-4-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-cyclopropyl-phenyl)-4-(1-(1-methylcyclopropyl)-indol-4-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-cyclopropyl-phenyl)-4-(1,2,3-trimethyl-indol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(1-methyl-3-ethyl-indol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(1,3-dimethyl-indol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(1-methyl-3-isopropyl-indol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(1,2-dimethyl-indol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(N-methyl-indol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1,3-dimethyl-indol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-cyclopropyl-phenyl)-4-(1,3-dimethyl-indol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-cyclopropyl-phenyl)-4-(1-methyl-indol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1H-indol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(1,2-dimethyl-indol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-ethyl-indol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-propyl-indol-5-yl)-5-mercapto-[1,2,4]triazole,     or a tautomer, or a pharmaceutically acceptable salt thereof.

In another embodiment, the compound is selected from the group consisting of

-   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(1-ethyl-benzimidazol-4-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(1-ethyl-benzimidazol-4-yl)-5-mercapto-[1,2,4]triazole     HCL salt, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(2-methyl-3-ethyl-benzimidazol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-ethyl-phenyl)-4-(1-ethyl-2-methyl-benzimidazol-5-yl)-5-mercapto-[1,2,4]triazole, -   3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-methyl-2-trifluoromethyl-benzimidazol-5-yl)-5-mercapto-[1,2,4]triazole,     or a tautomer, or a pharmaceutically acceptable salt thereof.

In another embodiment, the compound is selected from the group consisting of

-   5-hydroxy-4-(5-hydroxy-4-(1-methyl-1H-indol-5-yl)-4H-1,2,4-triazol-3-yl)-2-isopropylphenyl     dihydrogen phosphate, -   sodium     5-hydroxy-4-(5-hydroxy-4-(1-methyl-1H-indol-5-yl)-4H-1,2,4-triazol-3-yl)-2-isopropylphenyl     phosphate, -   2-(3,4-dimethoxyphenethyl)-5-hydroxy-4-(5-hydroxy-4-(1-methyl-1H-indol-5-yl)-4H-1,2,4-triazol-3-yl)phenyl     dihydrogen phosphate, -   5-hydroxy-2-isopropyl-4-(5-mercapto-4-(4-methoxybenzyl)-4H-1,2,4-triazol-3-yl)phenyl     dihydrogen phosphate, -   5-hydroxy-4-(5-hydroxy-4-(4-methoxybenzyl)-4H-1,2,4-triazol-3-yl)-2-isopropylphenyl     dihydrogen phosphate, -   4-(4-(1,3-dimethyl-1H-indol-5-yl)-5-hydroxy-4H-1,2,4-triazol-3-yl)-2-ethyl-5-hydroxyphenyl     dihydrogen phosphate, -   or a tautomer, or a pharmaceutically acceptable salt thereof.     Hsp90 inhibitory compounds, as well as tautomers or pharmaceutically     acceptable salts thereof, that may be used in the methods described     herein are depicted in Tables 1 or 2.

TABLE 1 STRUCTURE TAUTOMERIC STRUCTURE NAME 1

3-(2,4-DIHYDROXY-5- ISOPROPYL-PHENYL)-4-(1- METHYL-INDOL-5-YL)-5- HYDROXY-[1,2,4] TRIAZOLE 2

3-(2,4-DIHYDROXYPHENYL)-4- (1-ETHYL-INDOL-4-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE 3

3-(2,4-DIHYDROXY-PHENYL)-4- (2,3-DIMETHYL-1H-INDOL-4- YL)-5-MERCAPTO-[1,2,4] TRIAZOLE 4

3-(2,4-DIHYDROXYPHENYL)-4- (1-ISOPROPYL-INDOL-4-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE 5

3-(2,4-DIHYDROXY-PHENYL)-4- (INDOL-4-YL)-5-MERCAPTO- [1,2,3] TRIAZOLE 6

3-(2,4-DIHYDROXY-PHENYL)-4- [1-(2-METHOXYETHOXY)- INDOL-4-YL]-5-MERCAPTO- [1,2,4] TRIAZOLE 7

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-ISOPROPYL- INDOL-4-YL)-5-MERCAPTO- [1,2,4] TRIAZOLE 8

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-[1-(DIMETHYL- CARBAMOYL)-INDOL-4-YL]-5- MERCAPTO-[1,2,4] TRIAZOLE 9

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-ETHYL- BENZOIMIDAZOL-4-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE 10

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1,2,3-TRIMETHYL- INDOL-5-YL)-5-MERCAPTO- [1,2,4] TRIAZOLE 11

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-ISOPROPYL- INDOL-3-YL)-5-HYDROXY- [1,2,4] TRIAZOLE 12

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-ISOPROPYL- INDOL-4-YL)-5-AMINO-[1,2,4] TRIAZOLE 15

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-ISOPROPYL- INDOL-4-YL)-5-UREIDO-[1,2,4] TRIAZOLE 16

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-METHYL-INDOL- 4-YL)-5-CARBAMOYLOXY- [1,2,4] TRIAZOLE 17

3-(2,4-DIHYDROXY-PHENYL)-4- (1-METHYL-2-CHLORO-INDOL- 4-YL)-5-CARBAMOYLOXY- [1,2,4] TRIAZOLE 18

3-(2,4-DIHYDROXY-5- METHOXY-PHENYL)-4-(1- ISOPROPYL-BENZOIMIDAZOL- 4-YL)-5-(SULFAMOYLAMINO)- [1,2,4] TRIAZOLE 20

3-(2,4-DIHYDROXY-5- METHOXY-PHENYL)-4-(1- ISOPROPYL-BENZOIMIDAZOL- 4-YL)-5-(SULFAMOYLOXY)- [1,2,4] TRIAZOLE 21

3-(2-HYDROXY-4- ETHOXYCARBONYOXY-5- METHOXY-PHENYL)-4-(1- ISOPROPYL-BENZOIMIDAZOL- 4-YL)-5-HYDROXY-[1,2,4] TRIAZOLE 22

3-[2-HYDROXY-4- ISOBUTYRYLOXY-5-ETHYL- PHENYL]-4-(1-METHYL-BENZO- IMIDAZOL-4-YL)-5-HYDROXY- [1,2,4] TRIAZOLE 23

3-(2,4-DIHYDROXY-PHENYL)-4- (1-DIMETHYLCARBAMOYL- INDOL-4-YL)-5-MERCAPTO- [1,2,4] TRIAZOLE 24

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(2,3-DIMETHYL- INDOL-5-YL)-5-MERCAPTO- [1,2,4] TRIAZOLE 25

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-ETHYL-1H- BENZOIMIDAZOL-4-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE, HCL SALT 26

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-ISOPROPYL-7- METHOXY-INDOL-4-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE 27

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-PROPYL-INDOL- 4-YL)-5-MERCAPTO-[1,2,4] TRIAZOLE 28

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-ACETYL-2,3- DIMETHYL-INDOL-5-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE 29

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(2-METHYL-3- ETHYL-BENZIMIDAZOL-5-YL)- 5-MERCAPTO-[1,2,4] TRIAZOLE 30

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-ETHYL-2- METHYL-BENZIMIDAZOL-5- YL)-5-MERCAPTO-[1,2,4] TRIAZOLE 31

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-PROPYL-2,3- DIMETHYL-INDOL-5-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE 34

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-N-BUTYL-INDOL- 4-YL)-5-MERCAPTO-[1,2,4] TRIAZOLE 35

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-N-PENTYL- INDOL-4-YL)-5-MERCAPTO- [1,2,4] TRIAZOLE 36

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-N-HEXYL-INDOL- 4-YL)-5-MERCAPTO-[1,2,4] TRIAZOLE 37

3-(2,4-DIHYDROXY-5- CYCLOPROPYL-PHENYL)-4-(1- (1-METHYLCYCLOPROPYL)- INDOL-4-YL)-5-MERCAPTO- [1,2,4] TRIAZOLE 38

3-(2,4-DIHYDROXY-5- CYCLOPROPYL-PHENYL)-4-(1- ISOPROPYL-7-METHOXY- INDOL-4-YL)-5-MERCAPTO- [1,2,4] TRIAZOLE 39

3-(2,4-DIHYDROXY-5- CYCLOPROPYL-PHENYL)-4- (1,2,3-TRIMETHYL-INDOL-5- YL)-5-MERCAPTO-[1,2,4] TRIAZOLE 40

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-ISOPROPYL-7- METHOXY-INDOL-4-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE DISODIUM SALT 41

3-(2,4-DIHYDROXY-5-TERT- BUTYL-PHENYL)-4-(1- ISOPROPYL-7-METHOXY- INDOL-4-YL)-5-MERCAPTO- [1,2,4] TRIAZOLE 42

3-(2,4-DIHYDROXY-5- CYCLOPROPYL-PHENYL)-4-(1- PROPYL-7-METHOXY-INDOL-4- YL)-5-MERCAPTO-[1,2,4] TRIAZOLE 43

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-METHYL-3- ETHYL-INDOL-5-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE 44

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1,3-DIMETHYL- INDOL-5-YL)-5-MERCAPTO- [1,2,4] TRIAZOLE 45

3-(2,4-DIHYDROXY-5- ISOPROPYL-PHENYL)-4-(1- ISOPROPYL-7-METHOXY- INDOL-4-YL)-5-MERCAPTO- [1,2,4] TRIAZOLE 46

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-METHYL-3- ISOPROPYL-INDOL-5-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE 48

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-ISOPROPYL-7- HYDROXY-INDOL-4-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE 49

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1-ISOPROPYL-7- ETHOXY-INDOL-4-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE 50

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1,2-DIMETHYL- INDOL-5-YL)-5-MERCAPTO- [1,2,4] TRIAZOLE 51

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(N-METHYL-INDOL- 5-YL)-5-MERCAPTO-[1,2,4] TRIAZOLE 55

3-(2,4-DIHYDROXY-5- ISOPROPYL-PHENYL)-4-(1,3- DIMETHYL-INDOL-5-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE 56

3-(2,4-DIHYDROXY-5- CYCLOPROPYL-PHENYL)-4- (1,3-DIMETHYL-INDOL-5-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE 57

3-(2,4-DIHYDROXY-5-ETHYL- PHENYL)-4-(1,3-DIMETHYL- INDOL-5-YL)-5-HYDROXY- [1,2,4] TRIAZOLE 58

3-(2,4-DIHYDROXY-5- ISOPROPYL-PHENYL)-4-(N- METHYL-INDOL-5-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE 59

3-(2,4-DIHYDROXY-5- ISOPROPYL-PHENYL)-4-(1,2- DIMETHYL-INDOL-5-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE 60

3-(2,4-DIHYDROXY-5- ISOPROPYL-PHENYL)-4-(1,3- DIMETHYL-INDOL-5-YL)-5- HYDROXY-[1,2,4] TRIAZOLE 62

3-(2,4-DIHYDROXY-5- ISOPROPYL-PHENYL)-4-(1H- INDOL-5-YL)-5-MERCAPTO- [1,2,4] TRIAZOLE 63

3-(2,4-DIHYDROXY-5- ISOPROPYL-PHENYL)-4-(1- ETHYL-INDOL-5-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE 64

3-(2,4-DIHYDROXY-5- ISOPROPYL-PHENYL)-4-(1- PROPYL-INDOL-5-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE 65

3-(2,4-DIHYDROXY-5- ISOPROPYL-PHENYL)-4-(1- METHYL-2- TRIFLUOROMETHYL- BENZIMIDAZOL-5-YL)-5- MERCAPTO-[1,2,4] TRIAZOLE 66

3-(2,4-DIHYDROXY-5- ISOPROPYL-PHENYL)-4-(1- ISOPROPYL-INDOL-4-YL)-5- HYDROXY-[1,2,4] TRIAZOLE

TABLE 2 Compounds according to Formula (Ia) No. STRUCTURE TAUTOMERIC STRUCTURE NAME 1A

5-HYDROXY-4-(5- HYDROXY-4-(1- METHYL-1H-INDOL-5- YL)-4H-1,2,4-TRIAZOL- 3-YL)-2- ISOPROPYLPHENYL DIHYDROGEN PHOSPHATE 2A

SODIUM 5-HYDROXY-4- (5-HYDROXY-4-(1- METHYL-1H-INDOL-5- YL)-4H-1,2,4-TRIAZOL- 3-YL)-2- ISOPROPYLPHENYL PHOSPHATE 3A

2-(3,4- DIMETHOXYPHENETHYL)- 5-HYDROXY-4-(5- HYDROXY-4-(1- METHYL-1H-INDOL-5- YL)-4H-1,2,4-TRIAZOL- 3-YL)PHENYL DIHYDROGEN PHOSPHATE 4A

4-(4-(1,3-DIMETHYL-1H- INDOL-5-YL)-5- HYDROXY-4H-1,2,4- TRIAZOL-3-YL)-2- ETHYL-5- HYDROXYPHENYL DIHYDROGEN PHOSPHATE

The Hsp90 inhibitory compounds used in the disclosed combination therapies can be prepared according to the procedures disclosed in U.S. Patent Publication No. 2006/0167070 and WO2009/023211. These triazolone compounds typically can form a tautomeric structure as shown below and as exemplified by the tautomeric structures shown in Tables 1 and 2:

The present invention provides pharmaceutical combinations for the treatment, prophylaxis, and amelioration of proliferative disorders, such as cancer. In a specific embodiment, the combination comprises one or more Hsp90 inhibitors according to formulae (I) or (Ia), or a compound in Tables 1 or 2, or a tautomer or a pharmaceutically acceptable salt thereof in addition to an EGFR inhibitor.

In one embodiment, the combination includes a pharmaceutical composition or a single unit dosage form containing both an Hsp90 inhibitor and an EGFR inhibitor. Pharmaceutical combinations and dosage forms described herein comprise the two active ingredients in relative amounts and formulated in such a way that a given pharmaceutical combination or dosage form can be used to treat proliferative disorders, such as cancer. Preferred pharmaceutical combinations and dosage forms comprise a compound of formulae (I) or (Ia), or a compound in Tables 1 or 2, or a tautomer or pharmaceutically acceptable salt thereof, in combination with an EGFR inhibitor. In other embodiments, the Hsp90 inhibitor and the EGFR inhibitor may be in individual or separate pharmaceutical compositions, depending on the dosing schedules, preferred routes of administration, and available formulations of the two inhibitors. Optionally, these embodiments can also contain one or more additional therapeutic agents.

The pharmaceutical combinations described herein are formulated to be compatible with its intended route of administration. Examples of routes of administration include, parenteral, e.g., intravenous, intradermal, subcutaneous, oral (e.g., inhalation), intranasal, transdermal (topical), transmucosal, and rectal administration. In a specific embodiment, the combination is formulated in accordance with routine procedures as a pharmaceutical composition adapted for intravenous, subcutaneous, intramuscular, oral, intranasal or topical administration to human beings. In a preferred embodiment, the combination is formulated in accordance with routine procedures for subcutaneous administration to human beings.

In a specific embodiment, the combination therapies described herein comprise one or more compounds and at least one other therapy which has the same mechanism of action as said compounds. In another specific embodiment, the combination therapies described herein comprise one or more compounds described herein and at least one other therapy which has a different mechanism of action than said compounds. In certain embodiments, the combination therapies described herein improve the therapeutic effect of one or more triazolone compounds described herein by functioning together with the EGFR inhibitor to have an additive or synergistic effect. In certain embodiments, the combination therapies described herein reduce the side effects associated with the therapies. In certain embodiments, the combination therapies described herein reduce the effective dosage of one or more of the therapies.

In a specific embodiment, the combination comprising one or more triazolone compounds described herein is administered to a subject, preferably a human, to prevent, treat, manage, or ameliorate cancer, or one or more symptom thereof. In accordance with the invention, pharmaceutical combination described herein may also comprise one or more other agents being used, have been used, or are known to be useful in the treatment or amelioration of cancer, particularly non-small cell lung cancer, pancreatic cancer, ovarian cancer, gastrointestinal cancer, prostate cancer, rectal cancer, kidney cancer, liver cancer, gallbladder cancer, head and neck cancer, transitional cell carcinoma, squamous cell carcinoma, melanoma, glioblastoma, gliosarcoma, colorectal cancer, breast cancer, esophageal cancer, bladder cancer, hepatocellular carcinoma, renal cell carcinoma, brain and central nervous system cancer, neuroendocrine tumors, lymphoma, multiple myeloma, or chronic lymphocytic leukemia.

The pharmaceutical combinations described herein utilize pharmaceutical compositions and dosage forms which comprise one or more excipients. Suitable excipients are well known to those skilled in the art of pharmacy.

The triazolone compounds described herein can be also formulated into or administered by controlled release means or by delivery devices that are well known to those of ordinary skill in the art. Examples include those described in U.S. Pat. Nos. 3,845,770; 3,916,899; 3,536,809; 3,598,123; and 4,008,719, 5,674,533, 5,059,595, 5,591,767, 5,120,548, 5,073,543, 5,639,476, 5,354,556, and 5,733,566,

The present invention also includes a method of using the combination in treating a proliferative disorder in a subject, typically a human subject. More particularly, the method includes comprising administering to a subject in need thereof an effective amount of the pharmaceutical combination comprising an Hsp90 inhibitor and an EGFR inhibitor as described herein. In one embodiment, the proliferative disorder is cancer. In one aspect of this embodiment, the cancer is non-small cell lung cancer, pancreatic cancer, ovarian cancer, gastrointestinal cancer, prostate cancer, rectal cancer, kidney cancer, liver cancer, gallbladder cancer, head and neck cancer, transitional cell carcinoma, squamous cell carcinoma, melanoma, glioblastoma, gliosarcoma, colorectal cancer, breast cancer, esophageal cancer, bladder cancer, hepatocellular carcinoma, renal cell carcinoma, brain and central nervous system cancer, neuroendocrine tumors, lymphoma, multiple myeloma, or chronic lymphocytic leukemia. In one aspect of this embodiment, the cancer is locally advanced or metastatic non-small cell lung cancer or locally advanced, unresectable or metastatic pancreatic cancer.

In another embodiment, the proliferative disorder is associated with smooth muscle cell proliferation such as hyperproliferation of cells in the vasculature, for example, intimal smooth muscle cell hyperplasia, restenosis and vascular occlusion, particularly stenosis following biologically- or mechanically-mediated vascular injury, e.g., vascular injury associated with angioplasty. Moreover, intimal smooth muscle cell hyperplasia can include hyperplasia in smooth muscle other than the vasculature, e.g., bile duct blockage, bronchial airways of the lung in patients with asthma, in the kidneys of patients with renal interstitial fibrosis, and the like.

In a preferred embodiment, the proliferative disorder is cancer. Cancers that can be treated by the methods described herein include human sarcomas and carcinomas, e.g., fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, osteogenic sarcoma, chordoma, angiosarcoma, endotheliosarcoma, lymphangiosarcoma, lymphangioendotheliosarcoma, synovioma, mesothelioma, Ewing's tumor, leiomyosarcoma, rhabdomyosarcoma, colon carcinoma, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinomas, cystadenocarcinoma, medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma, hepatoma, bile duct carcinoma, choriocarcinoma, seminoma, embryonal carcinoma, Wilms' tumor, cervical cancer, testicular tumor, lung carcinoma, small cell lung carcinoma, bladder carcinoma, epithelial carcinoma, glioma, astrocytoma, medulloblastoma, craniopharyngioma, ependymoma, pinealoma, hemangioblastoma, acoustic neuroma, oligodendroglioma, meningioma, melanoma, neuroblastoma, retinoblastoma; leukemias, e.g., acute lymphocytic leukemia and acute myelocytic leukemia (myeloblastic, promyelocytic, myelomonocytic, monocytic and erythroleukemia); chronic leukemia (chronic myelocytic (granulocytic) leukemia and chronic lymphocytic leukemia); and polycythemia vera, lymphoma (Hodgkin's disease and non-Hodgkin's disease), multiple myeloma, Waldenstrobm's macroglobulinemia and heavy chain disease.

Other examples of leukemias include acute and/or chronic leukemias, e.g., lymphocytic leukemia, e.g., as exemplified by the p388 (murine) cell line, large granular lymphocytic leukemia, and lymphoblastic leukemia; T-cell leukemias, e.g., T-cell leukemia, as exemplified by the CEM, Jurkat, and HSB-2 (acute), YAC-1(murine) cell lines, T-lymphocytic leukemia, and T-lymphoblastic leukemia; B-cell leukemia, e.g., as exemplified by the SB (acute) cell line, and B-lymphocytic leukemia; mixed cell leukemias, e.g., B- and T-cell leukemia and B- and T-lymphocytic leukemia; myeloid leukemias, e.g., granulocytic leukemia, myelocytic leukemia, e.g., as exemplified by the HL-60 (promyelocyte) cell line, and myelogenous leukemia, e.g., as exemplified by the K562(chronic) cell line; neutrophilic leukemia; eosinophilic leukemia; monocytic leukemia, e.g., as exemplified by the THP-1(acute) cell line; myelomonocytic leukemia; Naegeli-type myeloid leukemia; and nonlymphocytic leukemia. Other examples of leukemias are described in Chapter 60 of THE CHEMOTHERAPY SOURCEBOOK (Michael C. Perry Ed., Williams & Williams (1992)) and Section 36 of HOLLAND FRIE CANCER MEDICINE (Bast et al. Eds., 5th ed., B.C. Decker Inc. (2000)).

In one embodiment, the disclosed method is believed to be effective in treating a subject with non-solid tumors such as multiple myeloma. In another embodiment, the disclosed method is believed to be effective against T-cell leukemia, e.g., as exemplified by Jurkat and CEM cell lines; B-cell leukemia, e.g., as exemplified by the SB cell line; promyelocytes, e.g., as exemplified by the HL-60 cell line; uterine sarcoma, e.g., as exemplified by the MES-SA cell line; monocytic leukemia, e.g., as exemplified by the THP-1(acute) cell line; and lymphoma, e.g., as exemplified by the U937 cell line.

In one embodiment, the disclosed method is believed to be effective in treating a subject with non-Hodgkin's lymphoma (NHL). Lymphomas are generally classified as either Hodgkin's disease (HD) or non-Hodgkin's lymphomas. NHL differs from HD by the absence of Reed-Sternberg cells. The course of NHL is less predictable than HD and is more likely to spread to areas beyond the lymph nodes. NHL can be further divided into B-cell NHL and T-cell NHL, each of which can be further categorized into a variety of different subtypes. For example, B-cell NHL includes Burkitt's lymphoma, follicular lymphoma, diffuse large B-cell lymphoma, nodal marginal zone B-cell lymphoma, plasma cell neoplasms, small lymphocytic lymphoma/chronic lymphocytic leukemia, mantle cell lymphoma, extranodal marginal zone B-cell lymphoma and lymphoplamacytic lymphoma/Waldenstrom macroglobulinemia. T-cell NHL includes anaplastic large-cell lymphoma, precursor-T-cell lymphoblastic leukemia/lymphoma, unspecified peripheral T-cell lymphoma, acute lymphoblastic leukemia/lymphoma, angioimmunoblastic T-cell lymphoma and mycosis fungoides.

Without wishing to be bound by any theory, it is believed that the Hsp90 inhibitory compounds used in the method described herein are useful for treating NHLs, including B-cell and T-cell NHLs, because Hsp90 is upregulated in many NHLs. In particular, in a survey of 412 cases of NHL in B-cell NHL, Hsp90 was found to be moderately to strongly over expressed in all cases of Burkitt's lymphoma (5/5, 100%), and in a subset of follicular lymphoma (17/28, 61%), diffuse large B-cell lymphoma (27/46, 59%), nodal marginal zone B-cell lymphoma (6/16, 38%), plasma cell neoplasms (14/39, 36%), small lymphocytic lymphoma/chronic lymphocytic leukemia (3/9, 33%), mantle cell lymphoma (12/38, 32%) and lymphoplamacytic lymphoma/Waldenstrom macroglobulinemia (3/10, 30%). In addition, in T-cell NHL, Hsp90 was found to be moderately to strongly over expressed in a subset of anaplastic large-cell lymphoma (14/24, 58%), precursor-T-cell lymphoblastic leukemia/lymphoma (20/65, 31%), unspecified peripheral T-cell lymphoma (8/43, 23%) and angioimmunoblastic T-cell lymphoma (2/17, 12%). Valbuena, et al., Modern Pathology (2005), 18:1343-1349.

Some of the disclosed methods can be particularly effective at treating subjects whose cancer has become “drug resistant” or “multi-drug resistant”. A cancer which initially responded to an anti-cancer drug becomes resistant to the anti-cancer drug when the anti-cancer drug is no longer effective in treating the subject with the cancer. For example, many tumors will initially respond to treatment with an anti-cancer drug by decreasing in size or even going into remission, only to develop resistance to the drug. “Drug resistant” tumors are characterized by a resumption of their growth and/or reappearance after having seemingly gone into remission, despite the administration of increased dosages of the anti-cancer drug. Cancers that have developed resistance to two or more anti-cancer drugs are said to be “multi-drug resistant”. For example, it is common for cancers to become resistant to three or more anti-cancer agents, often five or more anti-cancer agents and at times ten or more anti-cancer agents.

Other anti-proliferative or anti-cancer therapies may be combined with the compounds described herein to treat proliferative diseases such as cancer. Other therapies or anti-cancer agents that may be used in combination with the anti-cancer agents described herein include surgery, radiotherapy (including gamma-radiation, neutron beam radiotherapy, electron beam radiotherapy, proton therapy, brachytherapy, and systemic radioactive isotopes), endocrine therapy, biologic response modifiers (including interferons, interleukins, and tumor necrosis factor (TNF)), hyperthermia and cryotherapy, agents to attenuate any adverse effects (e.g., antiemetics), and other approved chemotherapeutic drugs.

The therapeutic agents of the combination therapies described herein can be administered sequentially or concurrently. In one embodiment, the administration of the Hsp90 inhibitor and the EGFR inhibitor are done concurrently. In another embodiment, the administration of the Hsp90 inhibitor and the EGFR inhibitor are done separately. In another embodiment, the administration of the Hsp90 inhibitor and the EGFR inhibitor are done sequentially. In another embodiment, the administration of the Hsp90 inhibitor is administered prior to or after the EGFR inhibitor. In one embodiment, the administration of the Hsp90 inhibitor and the EGFR inhibitor are done until the cancer is cured or stabilized or improved.

In one specific embodiment, the present method includes treating, managing, or ameliorating cancer, or one or more symptoms thereof, comprising administering to a subject in need thereof one or more compounds represented by the structural formulae (I) or (Ia) or a compound in Table 1 or Table 2, in combination with an EGFR inhibitor such as erlotinib, gefitinib or cetuximab, wherein the cancer is selected from the group consisting of non-small cell lung cancer, pancreatic cancer, ovarian cancer, gastrointestinal cancer, prostate cancer, small cell lung carcinoma, stomach cancer, cervical cancer, gastric cancer, rectal cancer, kidney cancer, liver cancer, gallbladder cancer, head and neck cancer, transitional cell carcinoma, squamous cell carcinoma, melanoma, glioblastoma, gliosarcoma, colorectal cancer, breast cancer, esophageal cancer, bladder cancer, hepatocellular carcinoma, renal cell carcinoma, brain and central nervous system cancer, neuroendocrine tumors, colon carcinoma, lymphoma, multiple myeloma, or chronic lymphocytic leukemia.

In another embodiment, the method of treating a subject with cancer includes administering to the subject an effective amount of a triazolone compound of 3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-methyl-indol-5-yl)-5-hydroxy-[1,2,4]triazole, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with an effective amount of an EGFR inhibitor.

In another embodiment, the method of treating a subject with cancer includes administering to the subject an effective amount of a triazolone compound of 3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-methyl-indol-5-yl)-5-hydroxy-[1,2,4]triazole, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with an effective amount of erlotinib.

In another embodiment, the method of treating a subject with cancer includes administering to the subject an effective amount of a triazolone compound of 5-hydroxy-4-(5-hydroxy-4-(1-methyl-1H-indol-5-yl)-4H-1,2,4-triazol-3-yl)-2-isopropylphenyl dihydrogen phosphate, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with an effective amount of an EGFR inhibitor.

In another embodiment, the method of treating a subject with cancer includes administering to the subject an effective amount of a triazolone compound of 5-hydroxy-4-(5-hydroxy-4-(1-methyl-1H-indol-5-yl)-4H-1,2,4-triazol-3-yl)-2-isopropylphenyl dihydrogen phosphate, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with an effective amount of erlotinib.

In another embodiment, the method of treating a subject with cancer includes administering to the subject an effective amount of a triazolone compound of 3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-methyl-indol-5-yl)-5-hydroxy-[1,2,4]triazole, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with an EGFR inhibitor such as erlotinib, gefitinib or cetuximab, wherein the cancer is selected from the group consisting of non-small cell lung cancer, pancreatic cancer, ovarian cancer, gastrointestinal cancer, prostate cancer, small cell lung carcinoma, stomach cancer, cervical cancer, gastric cancer, rectal cancer, kidney cancer, liver cancer, gallbladder cancer, head and neck cancer, transitional cell carcinoma, squamous cell carcinoma, melanoma, glioblastoma, gliosarcoma, colorectal cancer, breast cancer, esophageal cancer, bladder cancer, hepatocellular carcinoma, renal cell carcinoma, brain and central nervous system cancer, neuroendocrine tumors, colon carcinoma, lymphoma, multiple myeloma, or chronic lymphocytic leukemia.

In another embodiment, the method of treating a subject with cancer includes administering to the subject an effective amount of a triazolone compound of 5-hydroxy-4-(5-hydroxy-4-(1-methyl-1H-indol-5-yl)-4H-1,2,4-triazol-3-yl)-2-isopropylphenyl dihydrogen phosphate, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with an EGFR inhibitor such as erlotinib, gefitinib or cetuximab, wherein the cancer is selected from the group consisting of non-small cell lung cancer, pancreatic cancer, ovarian cancer, gastrointestinal cancer, prostate cancer, small cell lung carcinoma, stomach cancer, cervical cancer, gastric cancer, rectal cancer, kidney cancer, liver cancer, gallbladder cancer, head and neck cancer, transitional cell carcinoma, squamous cell carcinoma, melanoma, glioblastoma, gliosarcoma, colorectal cancer, breast cancer, esophageal cancer, bladder cancer, hepatocellular carcinoma, renal cell carcinoma, brain and central nervous system cancer, neuroendocrine tumors, colon carcinoma, lymphoma, multiple myeloma, or chronic lymphocytic leukemia.

In yet another embodiment, the method of treating a subject with cancer, wherein the subject is being or has been treated with a chemotherapeutic agent, includes administering to the subject an effective amount of a triazolone compound represented by the structural formulae (I) or (Ia) or a compound in Table 1 or Table 2, in combination with an EGFR inhibitor such as erlotinib, gefitinib or cetuximab.

In one embodiment, the method of treating a subject with cancer, wherein the subject is being or has been treated with a chemotherapeutic agent, includes administering to the subject an effective amount of a triazolone compound represented by the structural formulae (I) or (Ia) or a compound in Table 1 or Table 2, in combination with an EGFR inhibitor such as erlotinib, gefitinib or cetuximab, wherein the cancer is selected from the group consisting of non-small cell lung cancer, pancreatic cancer, ovarian cancer, gastrointestinal cancer, prostate cancer, small cell lung carcinoma, stomach cancer, cervical cancer, gastric cancer, rectal cancer, kidney cancer, liver cancer, gallbladder cancer, head and neck cancer, transitional cell carcinoma, squamous cell carcinoma, melanoma, glioblastoma, gliosarcoma, colorectal cancer, breast cancer, esophageal cancer, bladder cancer, hepatocellular carcinoma, renal cell carcinoma, brain and central nervous system cancer, neuroendocrine tumors, colon carcinoma, lymphoma, multiple myeloma, or chronic lymphocytic leukemia.

In another embodiment, the method of treating a subject with cancer, wherein the subject is being or has been treated with a chemotherapeutic agent, includes administering to the subject an effective amount of 3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-methyl-indol-5-yl)-5-hydroxy-[1,2,4]triazole, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with an EGFR inhibitor such as erlotinib, gefitinib or cetuximab.

In another embodiment, the method of treating a subject with cancer, wherein the subject is being or has been treated with a chemotherapeutic agent, includes administering to the subject an effective amount of 3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-methyl-indol-5-yl)-5-hydroxy-[1,2,4]triazole, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with erlotinib.

In another embodiment, the method of treating a subject with cancer, wherein the subject is being or has been treated with a chemotherapeutic agent, includes administering to the subject an effective amount of 5-hydroxy-4-(5-hydroxy-4-(1-methyl-1H-indol-5-yl)-4H-1,2,4-triazol-3-yl)-2-isopropylphenyl dihydrogen phosphate, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with an EGFR inhibitor such as erlotinib, gefitinib or cetuximab.

In another embodiment, the method of treating a subject with cancer, wherein the subject is being or has been treated with a chemotherapeutic agent, includes administering to the subject an effective amount of 5-hydroxy-4-(5-hydroxy-4-(1-methyl-1H-indol-5-yl)-4H-1,2,4-triazol-3-yl)-2-isopropylphenyl dihydrogen phosphate, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with erlotinib.

In one embodiment, the method of treating a subject with cancer, wherein the subject is being or has been treated with a chemotherapeutic agent, includes administering to the subject an effective amount of a triazolone compound of 3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-methyl-indol-5-yl)-5-hydroxy-[1,2,4]triazole, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with an EGFR inhibitor such as erlotinib, gefitinib or cetuximab, wherein the cancer is selected from the group consisting of non-small cell lung cancer, pancreatic cancer, ovarian cancer, gastrointestinal cancer, prostate cancer, small cell lung carcinoma, stomach cancer, cervical cancer, gastric cancer, rectal cancer, kidney cancer, liver cancer, gallbladder cancer, head and neck cancer, transitional cell carcinoma, squamous cell carcinoma, melanoma, glioblastoma, gliosarcoma, colorectal cancer, breast cancer, esophageal cancer, bladder cancer, hepatocellular carcinoma, renal cell carcinoma, brain and central nervous system cancer, neuroendocrine tumors, colon carcinoma, lymphoma, multiple myeloma, or chronic lymphocytic leukemia.

In one embodiment, the method of treating a subject with cancer, wherein the subject is being or has been treated with a chemotherapeutic agent, includes administering to the subject an effective amount of a triazolone compound of 5-hydroxy-4-(5-hydroxy-4-(1-methyl-1H-indol-5-yl)-4H-1,2,4-triazol-3-yl)-2-isopropylphenyl dihydrogen phosphate, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with an EGFR inhibitor such as erlotinib, gefitinib or cetuximab, wherein the cancer is selected from the group consisting of non-small cell lung cancer, pancreatic cancer, ovarian cancer, gastrointestinal cancer, prostate cancer, small cell lung carcinoma, stomach cancer, cervical cancer, gastric cancer, rectal cancer, kidney cancer, liver cancer, gallbladder cancer, head and neck cancer, transitional cell carcinoma, squamous cell carcinoma, melanoma, glioblastoma, gliosarcoma, colorectal cancer, breast cancer, esophageal cancer, bladder cancer, hepatocellular carcinoma, renal cell carcinoma, brain and central nervous system cancer, neuroendocrine tumors, colon carcinoma, lymphoma, multiple myeloma, or chronic lymphocytic leukemia.

In one embodiment, the method of treating a subject with cancer, wherein the subject has proven refractory to other therapies but is no longer on these therapies, includes administering to the subject an effective amount of a triazolone compound represented by the structural formulae (I) or (Ia) or a compound in Table 1 or Table 2, in combination with an EGFR inhibitor such as erlotinib, gefitinib or cetuximab, wherein the cancer is selected from the group consisting of non-small cell lung cancer, pancreatic cancer, ovarian cancer, gastrointestinal cancer, prostate cancer, small cell lung carcinoma, stomach cancer, cervical cancer, gastric cancer, rectal cancer, kidney cancer, liver cancer, gallbladder cancer, head and neck cancer, transitional cell carcinoma, squamous cell carcinoma, melanoma, glioblastoma, gliosarcoma, colorectal cancer, breast cancer, esophageal cancer, bladder cancer, hepatocellular carcinoma, renal cell carcinoma, brain and central nervous system cancer, neuroendocrine tumors, colon carcinoma, lymphoma, multiple myeloma, or chronic lymphocytic leukemia.

In another embodiment, the method of treating a subject with cancer, wherein the subject has proven refractory to other therapies but is no longer on these therapies, includes administering to the subject an effective amount of 3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-methyl-indol-5-yl)-5-hydroxy-[1,2,4]triazole, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with an EGFR inhibitor such as erlotinib, gefitinib or cetuximab.

In another embodiment, the method of treating a subject with cancer, wherein the subject has proven refractory to other therapies but is no longer on these therapies, includes administering to the subject an effective amount of 3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-methyl-indol-5-yl)-5-hydroxy-[1,2,4]triazole, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with erlotinib.

In another embodiment, the method of treating a subject with cancer, wherein the subject has proven refractory to other therapies but is no longer on these therapies, includes administering to the subject an effective amount of 5-hydroxy-4-(5-hydroxy-4-(1-methyl-1H-indol-5-yl)-4H-1,2,4-triazol-3-yl)-2-isopropylphenyl dihydrogen phosphate, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with an EGFR inhibitor such as erlotinib, gefitinib or cetuximab.

In another embodiment, the method of treating a subject with cancer, wherein the subject has proven refractory to other therapies but is no longer on these therapies, includes administering to the subject an effective amount of 5-hydroxy-4-(5-hydroxy-4-(1-methyl-1H-indol-5-yl)-4H-1,2,4-triazol-3-yl)-2-isopropylphenyl dihydrogen phosphate, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with erlotinib.

In one embodiment, the method of treating a subject with cancer, wherein the subject has proven refractory to other therapies but is no longer on these therapies, includes administering to the subject an effective amount of a triazolone compound of 3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-methyl-indol-5-yl)-5-hydroxy-[1,2,4]triazole, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with an EGFR inhibitor such as erlotinib, gefitinib or cetuximab, wherein the cancer is selected from the group consisting of non-small cell lung cancer, pancreatic cancer, ovarian cancer, gastrointestinal cancer, prostate cancer, small cell lung carcinoma, stomach cancer, cervical cancer, gastric cancer, rectal cancer, kidney cancer, liver cancer, gallbladder cancer, head and neck cancer, transitional cell carcinoma, squamous cell carcinoma, melanoma, glioblastoma, gliosarcoma, colorectal cancer, breast cancer, esophageal cancer, bladder cancer, hepatocellular carcinoma, renal cell carcinoma, brain and central nervous system cancer, neuroendocrine tumors, colon carcinoma, lymphoma, multiple myeloma, or chronic lymphocytic leukemia.

In one embodiment, the method of treating a subject with cancer, wherein the subject has proven refractory to other therapies but is no longer on these therapies, includes administering to the subject an effective amount of a triazolone compound of 5-hydroxy-4-(5-hydroxy-4-(1-methyl-1H-indol-5-yl)-4H-1,2,4-triazol-3-yl)-2-isopropylphenyl dihydrogen phosphate, or a tautomer, or a pharmaceutically acceptable salt thereof, in combination with an EGFR inhibitor such as erlotinib, gefitinib or cetuximab, wherein the cancer is selected from the group consisting of non-small cell lung cancer, pancreatic cancer, ovarian cancer, gastrointestinal cancer, prostate cancer, small cell lung carcinoma, stomach cancer, cervical cancer, gastric cancer, rectal cancer, kidney cancer, liver cancer, gallbladder cancer, head and neck cancer, transitional cell carcinoma, squamous cell carcinoma, melanoma, glioblastoma, gliosarcoma, colorectal cancer, breast cancer, esophageal cancer, bladder cancer, hepatocellular carcinoma, renal cell carcinoma, brain and central nervous system cancer, neuroendocrine tumors, colon carcinoma, lymphoma, multiple myeloma, or chronic lymphocytic leukemia.

In one further embodiment, the method includes inhibiting the growth of a cancer or tumor cell comprising the steps of: (a) contacting said cell with an effective amount of a compound of formulae (I) or (Ia) or a compound in Table (1) or Table (2), or tautomer or a pharmaceutically acceptable salt thereof; and (b) exposing said cell to an effective amount of an EGFR inhibitor such as erlotinib, gefitinib or cetuximab.

In one further embodiment, the method includes inhibiting the growth of a cancer or tumor cell comprising the steps of: (a) contacting said cell with an effective amount of a compound of -(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-methyl-indol-5-yl)-5-hydroxy-[1,2,4]triazole, or a tautomer, or a pharmaceutically acceptable salt thereof; and (b) exposing said cell to an effective amount of an EGFR inhibitor such as erlotinib, gefitinib or cetuximab.

In one further embodiment, the method includes inhibiting the growth of a cancer or tumor cell comprising the steps of: (a) contacting said cell with an effective amount of a compound of -(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-methyl-indol-5-yl)-5-hydroxy-[1,2,4]triazole, or a tautomer, or a pharmaceutically acceptable salt thereof; and (b) exposing said cell to an effective amount of erlotinib.

In one further embodiment, the method includes inhibiting the growth of a cancer or tumor cell comprising the steps of: (a) contacting said cell with an effective amount of a compound of 5-hydroxy-4-(5-hydroxy-4-(1-methyl-1H-indol-5-yl)-4H-1,2,4-triazol-3-yl)-2-isopropylphenyl dihydrogen phosphate, or tautomer or a pharmaceutically acceptable salt thereof; and (b) exposing said cell to an effective amount of an EGFR inhibitor such as erlotinib, gefitinib or cetuximab.

In one further embodiment, the method includes inhibiting the growth of a cancer or tumor cell comprising the steps of: (a) contacting said cell with an effective amount of a compound of 5-hydroxy-4-(5-hydroxy-4-(1-methyl-1H-indol-5-yl)-4H-1,2,4-triazol-3-yl)-2-isopropylphenyl dihydrogen phosphate, or tautomer or a pharmaceutically acceptable salt thereof; and (b) exposing said cell to an effective amount of erlotinib.

In general, the recommended daily dose range of a triazolone compound for the conditions described herein lie within the range of from about 0.01 mg to about 1000 mg per day, given as a single once-a-day dose preferably as divided doses throughout a day. In one embodiment, the daily dose is administered twice daily in equally divided doses. Specifically, a daily dose range should be from about 5 mg to about 500 mg per day, more specifically, between about 10 mg and about 200 mg per day. In managing the patient, the therapy should be initiated at a lower dose, perhaps about 1 mg to about 25 mg, and increased if necessary up to about 200 mg to about 1000 mg per day as either a single dose or divided doses, depending on the patient's global response. It may be necessary to use dosages of the active ingredient outside the ranges disclosed herein in some cases, as will be apparent to those of ordinary skill in the art. Furthermore, it is noted that the clinician or treating physician will know how and when to interrupt, adjust, or terminate therapy in conjunction with individual patient response.

Different therapeutically effective amounts may be applicable for different cancers, as will be readily known by those of ordinary skill in the art. Similarly, amounts sufficient to prevent, manage, treat or ameliorate such cancers, but insufficient to cause, or sufficient to reduce, adverse effects associated with the triazolone compounds described herein are also encompassed by the above described dosage amounts and dose frequency schedules. Further, when a patient is administered multiple dosages of a triazolone compound described herein, not all of the dosages need be the same. For example, the dosage administered to the patient may be increased to improve the prophylactic or therapeutic effect of the compound or it may be decreased to reduce one or more side effects that a particular patient is experiencing.

In a specific embodiment, the dosage of the composition comprising a triazolone compound described herein administered to prevent, treat, manage, or ameliorate cancer, or one or more symptoms thereof in a patient is 150 μg/kg, preferably 250 μg/kg, 500 μg/kg, 1 mg/kg, 5 mg/kg, 10 mg/kg, 25 mg/kg, 50 mg/kg, 75 mg/kg, 100 mg/kg, 125 mg/kg, 150 mg/kg, or 200 mg/kg or more of a patient's body weight. In another embodiment, the dosage of the composition comprising a compound described herein administered to prevent, treat, manage, or ameliorate cancer, or one or more symptoms thereof in a patient is a unit dose of 0.1 mg to 20 mg, 0.1 mg to 15 mg, 0.1 mg to 12 mg, 0.1 mg to 10 mg, 0.1 mg to 8 mg, 0.1 mg to 7 mg, 0.1 mg to 5 mg, 0.1 to 2.5 mg, 0.25 mg to 20 mg, 0.25 to 15 mg, 0.25 to 12 mg, 0.25 to 10 mg, 0.25 to 8 mg, 0.25 mg to 7 mg, 0.25 mg to 5 mg, 0.5 mg to 2.5 mg, 1 mg to 20 mg, 1 mg to 15 mg, 1 mg to 12 mg, 1 mg to 10 mg, 1 mg to 8 mg, 1 mg to 7 mg, 1 mg to 5 mg, or 1 mg to 2.5 mg. The unit dose can be administered 1, 2, 3, 4 or more times daily, or once every 2, 3, 4, 5, 6 or 7 days, or once weekly, once every two weeks, once every three weeks or once monthly.

In certain embodiments, when the triazolone compounds described herein are administered in combination with an EGFR inhibitor, the therapies are administered less than 5 minutes apart, less than 30 minutes apart, 1 hour apart, at about 1 hour apart, at about 1 to about 2 hours apart, at about 2 hours to about 3 hours apart, at about 3 hours to about 4 hours apart, at about 4 hours to about 5 hours apart, at about 5 hours to about 6 hours apart, at about 6 hours to about 7 hours apart, at about 7 hours to about 8 hours apart, at about 8 hours to about 9 hours apart, at about 9 hours to about 10 hours apart, at about 10 hours to about 11 hours apart, at about 11 hours to about 12 hours apart, at about 12 hours to 18 hours apart, 18 hours to 24 hours apart, 24 hours to 36 hours apart, 36 hours to 48 hours apart, 48 hours to 52 hours apart, 52 hours to 60 hours apart, 60 hours to 72 hours apart, 72 hours to 84 hours apart, 84 hours to 96 hours apart, or 96 hours to 120 hours part. In one embodiment, two or more therapies are administered within the same patient visit.

In certain embodiments, one or more compounds describer herein and one or more other the therapies (e.g., therapeutic agents) are cyclically administered. Cycling therapy involves the administration of a first therapy (e.g., a first prophylactic or therapeutic agents) for a period of time, followed by the administration of a second therapy (e.g., a second prophylactic or therapeutic agents) for a period of time, followed by the administration of a third therapy (e.g., a third prophylactic or therapeutic agents) for a period of time and so forth, and repeating this sequential administration, i.e., the cycle in order to reduce the development of resistance to one of the agents, to avoid or reduce the side effects of one of the agents, and/or to improve the efficacy of the treatment.

In certain embodiments, administration of the same compound described herein may be repeated and the administrations may be separated by at least 1 day, 2 days, 3 days, 5 days, 10 days, 15 days, 30 days, 45 days, 2 months, 75 days, 3 months, or 6 months. In other embodiments, administration of the same prophylactic or therapeutic agent may be repeated and the administration may be separated by at least at least 1 day, 2 days, 3 days, 5 days, 10 days, 15 days, 30 days, 45 days, 2 months, 75 days, 3 months, or 6 months.

In a specific embodiment, a method of preventing, treating, managing, or ameliorating a proliferative disorders, such as cancer, or one or more symptoms thereof, said methods comprising administering to a subject in need thereof a dose of at least 150 μg/kg, preferably at least 250 μg/kg, at least 500 μg/kg, at least 1 mg/kg, at least 5 mg/kg, at least 10 mg/kg, at least 25 mg/kg, at least 50 mg/kg, at least 75 mg/kg, at least 100 mg/kg, at least 125 mg/kg, at least 150 mg/kg, or at least 200 mg/kg or more of one or more compounds described herein once every day, preferably, once every 2 days, once every 3 days, once every 4 days, once every 5 days, once every 6 days, once every 7 days, once every 8 days, once every 10 days, once every two weeks, once every three weeks, or once a month. Alternatively, the dose can be divided into portions (typically equal portions) administered two, three, four or more times a day.

EXAMPLES Example 1 Compound 26 Displayed Anti-Tumor Activity Against Human Tumor Cells in a Nude Mouse Xenograft Model

The human squamous non-small cell lung cancer cell line, RERF-LC-AI (RCB0444; S. Kyoizumi, et al., Cancer. Res. 45:3274-3281, 1985), was obtained from the Riken Cell Bank (Tsukuba, Ibaraki, Japan). The cell line was cultured in growth media prepared from 50% Dulbecco's Modified Eagle Medium (high glucose), 50% RPMI Media 1640, 10% fetal bovine serum (FBS), 1% 100×L-glutamine, 1% 100× penicillin-streptomycin, 1% 100× sodium pyruvate and 1% 100×MEM non-essential amino acids. FBS was obtained from American Type Culture Collection (Manassas, Va., USA) and all other reagents were obtained from Invitrogen Corp. (Carlsbad, Calif., USA). Approximately 4-5×10(6) cells that had been cryopreserved in liquid nitrogen were rapidly thawed at 37° C. and transferred to a 175 cm² tissue culture flask containing 50 ml of growth media and then incubated at 37° C. in a 5% CO₂ incubator.

The growth media was replaced every 2-3 days until the flask became 90% confluent, typically in 5-7 days. To passage and expand the cell line, a 90% confluent flask was washed with 10 ml of room temperature phosphate buffered saline (PBS) and the cells were disassociated by adding 5 ml 1× trypsin-EDTA (Invitrogen) and incubating at 37° C. until the cells detached from the surface of the flask. To inactivate the trypsin, 5 ml of growth media was added and then the contents of the flask were centrifuged to pellet the cells. The supernatant was aspirated and the cell pellet was resuspended in 10 ml of growth media and the cell number determined using a hemocytometer. Approximately 1-3×10(6) cells per flask were seeded into 175 cm² flasks containing 50 ml of growth media and incubated at 37° C. in a 5% CO₂ incubator. When the flasks reached 90% confluence, the above passaging process was repeated until sufficient cells had been obtained for implantation into mice.

Seven to eight week old, female Crl:CD-1-nuBR (nude) mice were obtained from Charles River Laboratories (Wilmington, Mass., USA). Animals were housed 4-5/cage in micro-isolators, with a 12 hr/12 hr light/dark cycle, acclimated for at least 1 week prior to use and fed normal laboratory chow ad libitum. Studies were conducted on animals between 8 and 12 weeks of age at implantation. To implant RERF-LC-AI tumor cells into nude mice, the cells were trypsinized as above, washed in PBS and resuspended at a concentration of 50×10(6) cells/ml in 50% non-supplemented RPMI Media 1640 and 50% Matrigel Basement Membrane Matrix (#354234; BD Biosciences; Bedford, Mass., USA). Using a 27 gauge needle and 1 cc syringe, 0.1 ml of the cell suspension was injected subcutaneously into the flank of each nude mouse. Tumor volumes (V) were calculated by caliper measurement of the width (W), length (L) and thickness (T) of tumors using the following formula: V=0.5236×(L×W×T).

In vivo passaged RERF-LC-AI tumor cells (RERF-LC-AI^(IVP)) were isolated to improve the rate of tumor implantation relative to the parental cell line in nude mice. RERF-LC-AI tumors were permitted to develop in vivo until they reached approximately 250 mm³ in volume, which required approximately 3 weeks following implantation. Mice were euthanized via CO₂ asphyxiation and their exteriors sterilized with 70% ethanol in a laminar flow hood. Using sterile technique, tumors were excised and diced in 50 ml PBS using a scalpel blade. A single cell suspension was prepared using a 55 ml Wheaton Safe-Grind tissue grinder (catalog #62400-358; VWR International, West Chester, Pa., USA) by plunging the pestle up and down 4-5 times without twisting. The suspension was strained through a 70 μM nylon cell strainer and then centrifuged to pellet the cells. The resulting pellet was resuspended in 0.1 M NH₄Cl to lyse contaminating red blood cells and then immediately centrifuged to pellet the cells. The cell pellet was resuspended in growth media and seeded into 175 cm² flasks containing 50 ml of growth media at 1-3 tumors/flask or approximately 10×10(6) cells/flask. After overnight incubation at 37° C. in a 5% CO₂ incubator, non-adherent cells were removed by rinsing two times with PBS and then the cultures were fed with fresh growth media. When the flasks reached 90% confluence, the above passaging process was repeated until sufficient cells had been obtained for implantation into mice.

RERF-LC-AI^(IVP) cells were then implanted as above and tumors were permitted to develop in vivo until the majority reached an average of 100-200 mm³ in tumor volume, which typically required 2-3 weeks following implantation. Animals with oblong or very small or large tumors were discarded, and only animals carrying tumors that displayed consistent growth rates were selected for studies. Animals were randomized into treatment groups so that the average tumor volumes of each group were similar at the start of dosing.

The Hsp90 inhibitor, 17-allylamino-17-demethoxygeldanamycin (17-AAG), was employed as a positive control (Albany Molecular Research, Albany, N.Y., USA). Stock solutions of test articles were prepared by dissolving the appropriate amounts of each compound in dimethyl sulfoxide (DMSO) by sonication in an ultrasonic water bath. Stock solutions were prepared weekly, stored at −20° C. and diluted fresh each day for dosing. A solution of 20% Cremophore RH40 (polyoxyl 40 hydrogenated castor oil; BASF Corp., Aktiengesellschaft, Ludwigshafen, Germany) in 80% D5W (5% dextrose in water; Abbott Laboratories, North Chicago, Ill., USA) was also prepared by first heating 100% Cremophore RH40 at 50-60° C. until liquefied and clear, diluting 1:5 with 100% D5W, reheating again until clear and then mixing well. This solution was stored at room temperature for up to 3 months prior to use. To prepare formulations for daily dosing, DMSO stock solutions were diluted 1:10 with 20% Cremophore RH40. The final formulation for dosing contained 10% DMSO, 18% Cremophore RH40, 3.6% dextrose, 68.4% water and the appropriate amount of test article. Animals were intraperitoneally (i.p.) injected with this solution at 10 ml per kg body weight on a schedule of 5 days per week (Monday, Tuesday, Wednesday, Thursday and Friday, with no dosing on Saturday and Sunday) for a total of 15 doses.

As shown in FIG. 1, treatment with 200 mg/kg body weight of Compound 26 decreased the growth rate of RERF-LC-AI^(IVP) human lung tumor cells in nude mice, as did a dose of 75 mg/kg body weight of 17-AAG (an unrelated Hsp90 inhibitor). This effect was not associated with overt toxicity, as shown by the minimal effect on body weights depicted in FIG. 2.

Example 2 The Combination of Compound 1 and Erlotinib HCl Displayed Enhanced Anti-Tumor Activity Against Human Tumor Cells in a SCID Mouse Xenograft Model

The human non-small cell lung cancer (NSCLC) cell line, HCC827 (ATCC #CRL-2868) was obtained from the American Type Culture Collection (ATCC; Manassas, Va., USA).

HCC827 cells were cultured in growth media prepared from 50% Dulbecco's Modified Eagle Medium (high glucose), 50% RPMI Media 1640 (4.5 g/L glucose), 10% fetal bovine serum (FBS), 10 mM HEPES, 1% 100× Penicillin-Streptomycin, 1% 100× sodium pyruvate and 1% 100×MEM non-essential amino acids. FBS was obtained from ATCC and all other reagents were obtained from Invitrogen Corp. (Carlsbad, Calif., USA). Cells that had been cryopreserved in liquid nitrogen were rapidly thawed at 37° C. and transferred to a tissue culture flask containing growth media and then incubated at 37° C. in a 5% CO₂ incubator. To expand the HCC827 cell line, cultures were split 1:3 every 3 days when 175 cm² flasks became 85% confluent. Cultures were passaged by washing with 10 mL of room temperature phosphate buffered saline (PBS) and then disassociating cells by adding 5 mL 1× trypsin-EDTA and incubating at 37° C. until the cells detached from the surface of the flask. To inactivate the trypsin, 5 mL of growth media was added and then the contents of the flask were centrifuged to pellet the cells. The supernatant was aspirated and the cell pellet was resuspended in 10 mL of growth media and the cell number determined using a hemocytometer. Cells were seeded into 175 cm² flasks containing 50 mL of growth media and incubated at 37° C. in a 5% CO₂ incubator. When the flasks reached 85% confluence, the above passaging process was repeated until sufficient cells had been obtained for implantation into mice.

Six to eight week old, female CB17/Icr-Prkdc^(scid)/Crl (SCID) mice were obtained from Charles River Laboratories (Wilmington, Mass., USA). Animals were housed 4-5/cage in micro-isolators, with a 12 hr/12 hr light/dark cycle, acclimated for at least 1 week prior to use and fed normal laboratory chow ad libitum. Animals were between seven to twelve weeks of age at implantation. To implant HCC827 tumor cells into SCID mice, cells were collected as described above, washed in PBS and resuspended at a concentration of 5×10(7) cells/mL in 50% non-supplemented medium and 50% Matrigel Basement Membrane Matrix (#354234; BD Biosciences; Bedford, Mass., USA). Using a 27 gauge needle and 1 cc syringe, 5×10(6) HCC827 cells in 0.1 mL of a cell suspension were injected subcutaneously into the flanks of SCID mice.

For the HCC827 model, tumors were then permitted to develop in vivo until the majority reached approximately 100-200 mm³ in tumor volume, which required ˜2 weeks. Animals with oblong, very small or large tumors were discarded and only animals carrying tumors that displayed consistent growth rates were selected for studies. Tumor volumes (V) were calculated by caliper measurement of the width (W), length (L) and thickness (T) of tumors using the following formula: V=0.5236×(L×W×T). Animals were randomized into treatment groups so that the average tumor volumes of each group were similar at the start of dosing. % T/C values, as a measure of efficacy, were determined as follows:

-   (i) If ΔT>0: % T/C=(ΔT/ΔC)×100 -   (ii) If ΔT<0: % T/C=(ΔT/T₀)×100 -   (iii) ΔT=Change in average tumor volume between start of dosing and     the end of study. -   (iv) ΔC=Change in average tumor volume between start of dosing and     the end of study. -   (v) T₀=Average tumor volume at start of dosing.

To formulate the test article, Compound 1, in DRD, stock solutions of the test article were prepared by dissolving the appropriate amounts of the compound in dimethyl sulfoxide (DMSO) by sonication in an ultrasonic water bath. Stock solutions were prepared weekly, stored at −20° C. and diluted fresh each day for dosing. A solution of 20% Cremophore RH40 (polyoxyl 40 hydrogenated castor oil; BASF Corp., Aktiengesellschaft, Ludwigshafen, Germany) in 5% dextrose in water (Abbott Laboratories, North Chicago, Ill., USA) was also prepared by first heating 100% Cremophore RH40 at 50-60° C. until liquefied and clear, diluting 1:5 with 100% D5W, reheating again until clear and then mixing well. This solution can be stored at room temperature for up to 3 months prior to use. To prepare DRD formulations for daily dosing, DMSO stock solutions were diluted 1:10 with 20% Cremophore RH40. The final DRD formulation for dosing contained 10% DMSO, 18% Cremophore RH40, 3.6% dextrose, 68.4% water and the appropriate amount of test article. Animals were intravenous (i.v.) injected via the tail vein with this formulation at 10 mL per kg body weight on 1 day each week. Erlotinib HCl (Tarceva) was purchased from LGM Pharmceuticals (Boca Raton, Fla., USA), stored at 4° C., and the appropriate amount of the test article was dissolved in 1% Tween 80 in PBS by sonication in an ultrasonic water bath. Animals were orally (p.o.) dosed by gavage with this formulation at 5 mL per kg body weight on 1 day each week.

The combination of Compound 1 and erlotinib HCl was examined in the human HCC827 NSCLC xenograft model. As shown in FIG. 3, treatment with a dose of 50 mg/kg body weight of Compound 1 on a once per week schedule moderately inhibited HCC827 tumor growth in SCID mice, with a % T/C value of 15 observed on day 34. Similarly, treatment with a dose of 25 mg/kg body weight of erlotinib HCl on a once per week schedule moderately inhibited HCC827 tumor growth in SCID mice, with a % T/C value of 23 observed on day 34. In contrast, concurrent treatment with a combination of 50 mg/kg body weight of Compound 1 plus 25 mg/kg body weight erlotinib HCl on a once per week schedule dramatically inhibited tumor growth and induced tumor regression, with a % T/C value of −31 observed on day 34. The efficacy observed for the combination treatment group was significantly greater than that observed for either single-agent group alone (P<0.05; one-way ANOVA). This effect was not associated with excessive toxicity, as the Compound 1 plus erlotinib HCl combination treatment group had an average bodyweight change on day 34 relative to the start of the study of +6.9% (+/−1.1 SEM), as compared to +2.4% (+/−1.1 SEM) for the vehicle-treated group. In separate studies, similar results were also observed combining 50 mg/kg Compound 1 with either 15 or 50 mg/kg body weight erlotinib HCl dose on a once per week schedule in this model.

To examine the potential for drug-drug interactions between Compound 1 and erlotinib HCl, an in vivo pharmacokinetic study was conduced. Six to eight week old, female CB17/Icr-Prkdc^(scid)/Crl (SCID) mice were obtained from Charles River Laboratories (Wilmington, Mass., USA). Animals were housed 4-5/cage in micro-isolators, with a 12 hr/12 hr light/dark cycle, acclimated for at least 1 week prior to use and fed normal laboratory chow ad libitum. Animals (3/time point) were i.v. dosed a single time with 50 mg/kg body weight Compound 1 alone, 25 mg/kg body weight erlotinib HCl alone, or a combination of 50 mg/kg body weight Compound 1 plus 25 mg/kg body weight erlotinib HCl. Blood samples were withdrawn at multiple time points (0.083, 0.25, 0.5, 1, 2, 4, 6, 8, 24 hr), plasma prepared, and the concentrations of Compound 1 and erlotinib HCl were determined by HPLC. As shown in Table 1, Erlotinib HCl had no significant effect on the plasma half-life (t^(1/2)), peak plasma concentration (Cmax) or total plasma exposure (AUCinf) of Compound 1. Similarly, Compound 1 had little or no effect on the plasma half-life (t^(1/2)), peak plasma concentration (Cmax) or total plasma exposure (AUCinf) of erlotinib HCl. The 39% increase in total plasma exposure of erlotinib HCl was within the experimental error of this study and, based on the dose response of erlotinib HCl in this model (data not shown), was unlikely to account for the increased efficacy observed for the combination of Compound 1 and erlotinib HCl relative to either single agent alone.

TABLE 1 HPLC DOSE AUCINF TREATMENT ANALYTE (MG/KG) T½ (HR) CMAX (μM) (μMXHR) COMPOUND 1 COMPOUND 1 50 4.7 118 38.5 COMPOUND 1 + COMPOUND 1 50 4.5 93.4 36.0 ERLOTINIB HCL ERLOTINIB HCL ERLOTINIB 25 1.7 4.11 28.1 HCL ERLOTINIB HCL + ERLOTINIB 25 2.8 4.94 39.0 COMPOUND 1 HCL

In conclusion, the combination of Compound 1 and erlotinib HCl displayed greater efficacy than either single agent alone. Combination treatment did not result in additional toxicity relative to the single agents, with only minimal effects on cumulative average body weight changes over the course of the study. Erlotinib HCl did not affect the plasma exposure of Compound 1 in SCID mice. Compound 1 had little effect on the plasma exposure of erlotinib in SCID mice. Error bars represent +/−SEM for efficacy studies and +/−SD for the PK study.

All publications, patent applications, patents, and other documents cited herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples throughout the specification are illustrative only and not intended to be limiting in any way. 

1-9. (canceled)
 10. A method of treating cancer in a subject, comprising administering to the subject an effective amount of a compound, which is 3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-methyl-indol-5-yl)-5-hydroxy-[1,2,4]triazole, 5-hydroxy-4-(5-hydroxy-4-(1-methyl-1H-indol-5-yl)-4H-1,2,4-triazol-3-yl)-2-isopropylphenyl dihydrogen phosphate, or a tautomer, or a pharmaceutically acceptable salt thereof, and an effective amount of an EGFR inhibitor. 11-12. (canceled)
 13. The method of claim 10, wherein the cancer is pancreatic cancer, ovarian cancer, gastrointestinal cancer, prostate cancer, rectal cancer, kidney cancer, liver cancer, gallbladder cancer, head and neck cancer, transitional cell carcinoma, squamous cell carcinoma, melanoma, glioblastoma, gliosarcoma, colorectal cancer, breast cancer, esophageal cancer, bladder cancer, hepatocellular carcinoma, renal cell carcinoma, brain and central nervous system cancer, neuroendocrine tumors, lymphoma, multiple myeloma, or chronic lymphocytic leukemia.
 14. The method of claim 13, wherein the cancer is pancreatic cancer. 15-19. (canceled)
 20. The method of claim 10, wherein the subject is human. 21-26. (canceled)
 27. The method of claim 10, wherein the compound is 3-(2,4-dihydroxy-5-isopropyl-phenyl)-4-(1-methyl-indol-5-yl)-5-hydroxy-[1,2,4]triazole, or a tautomer or a pharmaceutically acceptable salt thereof.
 28. The method of claim 10, wherein the EGFR inhibitor is gefitinib or cetuximab.
 29. The method of claim 10, wherein the cancer is pancreatic cancer and the EGFR inhibitor is gefitinib or cetuximab. 